We developed a honey bee RNA-virus vector based on the genome of a picorna-like Deformed wing virus (DWV), the main viral pathogen of the honey bee (Apis mellifera). To test the potential of DWV to be utilized as a vector, the 717 nt sequence coding for the enhanced green fluorescent protein (eGFP), flanked by the peptides targeted by viral protease, was inserted into an infectious cDNA clone of DWV in-frame between the leader protein and the virus structural protein VP2 genes. The in vitro RNA transcripts from egfp-tagged DWV cDNA clones were infectious when injected into honey bee pupae. Stable DWV particles containing genomic RNA of the recovered DWV with egfp inserts were produced, as evidenced by cesium chloride density gradient centrifugation. These particles were infectious to honey bee pupae when injected intra-abdominally. Fluorescent microscopy showed GFP expression in the infected cells and Western blot analysis demonstrated accumulation of free eGFP rather than its fusions with DWV LP and/or VP2 proteins. Analysis of the progeny egfp-tagged DWV showed gradual accumulation of genome deletions for egfp, providing estimates for the rate of loss of a non-essential gene an insect RNA virus genome during natural infection.

Aim: Streptococcus pneumoniae and influenza H1N1 virus are common organisms associated with human infections. These infections could play a significant role in immune regulation. The study was performed to analyse the genome sequences of these organisms with human genome and study its functional significance. Methods: The study was performed to analyse the overlapping of genome sequences in Streptococcus pneumoniae and Influenza (H1N1) virus against human genome sequences by BLASTn sequence analysis. The alignments are studied against the corresponding genes for their functional significance with DAVID and NDEx software.Results: Several hits or overlapping nucleotide segments were identified. Between streptococcus and homo sapiens 287 overlaps were identified, and among influenza and homo sapiens 124 hits were identified. A wide range of functional significance of these genes were identified, and the results are presented in this study. The results show insights into functional pathways and biological activities associated with the respective vaccinations or infections by these microorganisms. Conclusion: The common organisms like Streptococcus pneumoniae and Influenza H1N1 virus actively interact with the immune system and result in a wide range of immune regulations.

The rapid development of 2019-2020 Wuhan seafood market pneumonia currently posed a major public health concern in China. Genome sequencing identified a novel beta-coronavirus closely related to SARS-CoV, named 2019-nCoV by WHO, as the cause of this pandemic disease. Viruses with single stranded RNA genome are prone to evolve quickly by accumulation of mutations, such as SNV, INDEL and cross viral recombination, aiding fast transmission among hosts and cross species. Here we collected related genome sequences and investigated variations shared by different strains of 2019-nCoV, identified reoccurrence of SNV mutations in clusters of patients, an indication of rapid evolution of 2019-nCoV at the transmission from animal host to human. The information collected herein would help to understand the dynamics of current pandemic.

"Medusaviridae" is a proposed family of large DNA viruses so far represented by a sole virus isolated from a hot spring. In the present study, we report the isolation and genome sequencing of a new member of this family, medusavirus stheno, discovered from a freshwater sample with Acanthamoeba castellanii coculture.

Novel segmented tick-borne RNA viruses belonging to the group of Jingmenviruses (JMVs) are widespread across Africa, Asia, Europe, and America. In this work, we obtained whole-genome sequences of two Kindia tick virus (KITV) isolates and performed modeling and functional annotation of the secondary structure of 5’ and 3’ UTRs from JMV and KITV viruses. UTRs of various KITV segments are characterized by: (1) polyadenylated 3’ UTRs; (2) 5’ DAR and 3’ DAR motifs; (3) a highly conserved 5’-CACAG-3’ pentanucleotide; (4) a La protein binding site; (5) multiple UAG sites providing interactions with the MSI1 protein; (6) three homologous sequences in the 5’ UTR and 3’ UTR of segment 2; (7) the segment 2 3’ UTR of a KITV/2017/1 isolate comprises two consecutive 40 nucleotide repeats forming a Y-3 structure; (8) a 35-nucleotide deletion in the second repeat of the segment 2 3’ UTR of KITV/2018/1 and KITV/2018/2 isolates, leading to a modification of the Y-3 structure; (9) two pseudoknots in the segment 2 3’ UTR; (10) the 5’ UTR and 3’ UTR are represented by patterns of conserved motifs; (11) the 5’-CAAGUG-3’ sequence occurs in early UTR hairpins. Thus, we identified regulatory elements in the UTRs of KITV, which are characteristic of orthoflaviviruses. This suggests their functional significance for the replication of JMVs and the evolutionary similarity between orthoflaviviruses and segmented flavi-like viruses.

Enterovirus A71 (EV-A71) infection is a major cause of hand, foot and mouth disease (HFMD) which may be occasionally associated with severe neurological complications. There are currently a lack of treatment options for EV-A71 infection. The Raf-MEK-ERK signaling pathway, in addition to its critical importance in the regulation of cell growth, differentiation and survival, has been shown to be essential for virus replication. In this study, we investigated the anti-EV-A71 activity of vemurafenib, a clinically approved B-Raf inhibitor used in the treatment of late stage melanoma. Vemurafenib exhibits potent anti-EV-A71 effect in cytopathic effect inhibition and viral load reduction assays, with half maximal effective concentration (EC50) at nanomolar concentration. Mechanistically, vemurafenib interrupts both EV-A71 genome replication and assembly. These findings expand the list of potential antiviral candidates of anti-EV-A71 therapeutics.

Cotton leaf curl Kokhran virus (CLCuKoV) (genus, Begomovirus; family, Geminiviridae) is highly infectious, widespread and the most dangerous pathogen of cotton (Gossypium hirsutum L.) that is responsible to a serious disorder, cotton leaf curl disease (CLCuD). Begomoviruses are spread very efficiently by the whitefly Bemisia tabaci cryptic species, causing economic losses to cotton crop, all over the world. The ‘Lucknow’ strain of CLCuKoV has emerged as a divergent isolate that could cause CLCuD. The monopartite ssDNA genome of CLCuKoV-Lu (2.7 Kb) contains six open reading frames (ORFs) that was shown to encode four major proteins. RNA interference (RNAi)-based antiviral innate immunity is a sequence-specific biological phenomenon and a powerful tool to control plant viruses. The present study aims to determine cotton locus-derived microRNAs (ghr-miRNAs) that are identified for targeting the CLCuKoV-Lu ss-DNA-encoded mRNAs using a predictive approach that involves four computational algorithms, miRanda, RNA22, psRNATarget and RNAhybrid. Mature ghr-miRNA sequences (n=80) from allotetraploid upland cotton (2n = 4x = 52) were selected from the miRBase and were tested for alignment with the CLCuKoV-Lu genome. Among the 80 cotton locus-derived ghr-miRNAs evaluated, only one consensus cotton locus-derived ghr-miRNA (ghr-miR2950) was concluded to have effective ghr-miRNA target site at common nucleotide position 82 in the CLCuKoV-Lu genome respectively, using a stringent criterion, identified by all the algorithms used. The miRNA targeting is reliant on base pairing of miRNA-mRNA target pairings. Conservation of the hybridization binding site of the predicted ghr-miR2950 was validated using multiple sequence alignment within all the strains of CLCuKoV. We constructed a regulatory interaction network of miRNA–mRNA to identify novel targets. The efficacy of the predicted miRNAs against CLCuKoV-Lu was evaluated by RNAi-mediated targeted mRNA cleavage. The current investigated miRNA targets provide evidence for the development of CLCuD-resistant cotton plants.

The Chinese honeybee (Apis cerana cerana) sacbrood virus (CSBV) causes death of larvae and colony collapse, and could damage the beekeeping industry in China. We sequenced complete genomes of CSBV strains derived from the Maerkang area, Wenjiang area, and Wanyuan area of Sichuan province of China. The genome length of CSBV strains from Sichuan was 8863bp, and it contained one complete Open Reading Frame of a gene with 8544 bp that encoded a protein with 2848 amino acids. The (G+C) % and (A+T) % composition ranged from 40.6 to 40.7 and 59.3 to 59.4, respectively. A phylogenetic tree was constructed using the three CSBV strains and previously reported SBV and CSBV sequences from other regions. We found that viral strains clustered based on their region of origin and host species. The genetic sequences of the CSBV strain from Maerkang were 98.7% and 99.6% similar to CSBV strains from Wanyuan and Wenjiang, respectively. In addition, CSBV from Maerkang had 88.4%-95.2% sequence similarity to previously published genomes of CSBV or SBV from other areas. The VP1 gene sequenced in our study had a 43 bp deletion compared to VP1 sequences of CSBV from other regions in Asia. We detected 10 antigenic determinants on the VP1 protein of CSBV form Aba. Our study provides new insight into the diversity of CSBV strains in China and may help with identifying methods to prevent infection of honeybee colonies.

Sugarcane mosaic virus (SCMV) is a (genus, Potyvirus; family, Potyviridae) is a widespread, deleterious, and the most damaging pathogen of sugarcane ((Saccharum officinarum L. and Saccharum spp.) which causes a substantial barrier to producing high sugarcane earning. Sugarcane mosaic disease (SCMD) is caused by, single or compound infection of SCMV, disseminated by the several aphid vectors in a non-persistent manner. SCMV has flexuous filamentous particle of 700-750 nm long, which encapsidated a positive-sense, single-stranded RNA molecule of 9575 nucleotides. RNA interference (RNAi)-mediated antiviral innate immunity is an evolutionary conserved, key biological process in eukaryotes and has evolved as an antiviral defence system to interfere with viral genomes for controlling infections in plants. The current study aims to analyze sugarcane (Saccharum officinarum L. and Saccharum spp.) locus-derived microRNAs (sof-miRNAs/ssp-miRNAs) with predicted potential for targeting the SCMV +ssRNA-encoded mRNAs, using a predictive approach that involves five algorithms. The ultimate goal of this research is to mobilize the in silico- predicted endogenous sof-miRNAs/ssp-miRNAs to experimentally trigger the catalytic RNAi pathway and generate sugarcane cultivars to evaluate the potential antiviral resistance surveillance ability and capacity for SCMV. Experimentally validated mature sugarcane (S. officinarum, 2n = 8X = 80) and (S. spp., 2n = 100-120) sof-miRNA/ssp-miRNA sequences (n = 28) were downloaded from the miRBase database and aligned with the SCMV genome (KY548506). Among the 28 targeting mature locus-derived sof-miRNAs/ssp-miRNAs evaluated, one sugarcane miRNA homolog, sof-miR159c, was identified to have a predicted miRNA binding site, at nucleotide position 3847 of the SCMV genome targeting CI ORF. To verify the accuracy of the target prediction accuracy and to determine, whether the sugarcane sof-miRNA/ssp-miRNA could bind the predicted SCMV mRNA target(s), we constructed an integrated Circos plot. A genome-wide in-silico-predicted miRNA-mediated target gene regulatory network has implicated to validate interactions necessary to warrant in vivo analysis. The current work provides valuable computational evidence for the generation of SCMV-resistant sugarcane cultivars.

A novel virus with distinct genome features was discovered by high throughput sequencing in a symptomatic blackcurrant plant. The virus tentatively named as blackcurrant virus A (BCVA) has distinct genome organization and molecular features bridging genera in the order Tymovirales. The genome consists of 7106 nucleotides excluding the poly(A) tail. Five open reading frames were identified with the first encoding a putative viral replicase with methyl transferase (MTR), AlkB, helicase and RNA dependent RNA polymerase (RdRp) domains. The other four putative proteins exhibit no significant homology to other virus proteins. The genome organization downstream of the replicase resembles that of members of the order Tymovirales with an unconventional triple gene block (TGB) movement protein arrangement. Phylogenetic analysis using replicase conserved motifs loosely placed BCVA within the Betaflexiviridae whereas it was evolutionarily distant to existing members of the family when using the putative TGBp 1-like and coat protein sequences. Our analysis strongly suggests that BCVA is a novel virus that should be classified as a species in a new genus in the Betaflexiviridae or a new family in the order Tymovirales.

In December 2019, pneumonia caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection emerged in Wuhan City, Hubei Province, China. Early in 2020, the World Health Organization (WHO) announced a new name for the 2019-nCoV-caused epidemic disease: coronavirus disease 2019 (COVID-19) and declared COVID-19 to be the sixth international public health emergency. Cellular co-infection is a critical determinant of both viral fitness and infection outcome and plays a crucial role in shaping the host immune response to infections. In this study, sixty-eight public next-generation sequencing libraries from SARS-CoV-2 infected patients were retrieved from the NCBI Sequence Read Archive database using SRA-Toolkit. Using an alignment-free method based on K-mer mapping and extension, SARS-CoV-2 was identified in all except three patients. Influenza A H7N9 (3/68), Human immunodeficiency virus 1 (1/68), rhabdovirus isolate (3/68), Human metapneumovirus (1/68), coronaviruses NL63 (1/68), Parvovirus (1/68), Simian virus 40 (1/68), and hepatitis virus (1/68) genome sequences were detected in SARS-CoV-2 infected patients.

Foot-and-mouth disease virus (FMDV) causes the highly contagious foot-and-mouth disease, which is characterized by the appearance of vesicles in and around the mouth and feet of cloven-hoofed animals. BHK21 cells are the cell line of choice for the propagation of FMDV for vaccine production world-wide but vary in their susceptibility for different FMDV strains. Previous studies showed that the FMDV resistance of a certain BHK cell line can be overcome by using a closely related but permissive cell line for the pre-adaptation of the virus, but the adapted strains were found to harbor several capsid mutations. In this study, these adaptive mutations were introduced into the original Asia-1 Shamir isolate individually or in combination to create a panel of 17 Asia-1 mutants by reverse genetics and examine the effects of the mutations on receptor usage, viral growth, immunogenicity and stability. A single amino acid exchange from glutamic acid to lysine at position 202 in VP1 turned out to be of major importance for productive infection of the suspension cell line BHK-2P. In consequence, two traditionally passage-derived strains and two recombinant viruses with a minimum set of mutations were tested in vivo. While the passaged-derived viruses showed a reduced particle stability, the genetically modified viruses were more stable but did not confer a protective immune response against the original virus isolate.

Sugarcane mosaic virus (SCMV) is a deleterious pathogen which causes widespread Sugarcane mosaic disease (SCMD) and is classified in the genus Potyvirus (Potyviridae), disseminated by the aphid vector. RNA interference (RNAi)-mediated antiviral innate immunity is a key biological process and antiviral defence system to interfere with viral genomes for controlling plant pathogens. The current study aims to analyze sugarcane (Saccharum officinarum L. and Saccharum spp.) locus-derived microRNAs (sof-miRNAs/ssp-miRNAs) with predicted potential for targeting the SCMV +ssRNA-encoded mRNAs, using ‘five algorithms’ approach. The ultimate goal in this research is to mobilize the in silico endogenous predicted sof-miRNAs/ssp-miRNAs to trigger RNAi catalytic pathway experimentally and generate sugarcane cultivars for evaluating potential antiviral resistance monitoring capability and capacity for SCMV. Experimentally validated mature sugarcane (S. officinarum, 2n = 8X = 80) and (S. spp., 2n = 100-120) sof-miRNAs/ssp-miRNAs (n = 28) were acquired for alignment with the SCMV genome. Of the 28 targeting mature locus-derived sof-miRNAs/ssp-miRNAs investigated, one sugarcane miRNA homolog, sof-miR159c, was concluded to localize potential binding site at genomic nucleotide site 3847 targeting CI ORF of SCMV. In order to validate target prediction accuracy, whether the sugarcane sof-miRNA/ssp-miRNA might bind predicted SCMV mRNA target(s), we created an integrated Circos plot. Genome-wide in-silico-predicted miRNA-mediated target gene regulatory network validated interactions that warrant in vivo analysis. The current work provides valuable evidence and biological material for generating SCMV-resistant sugarcane varieties.

The production and quality of Phaseolus vulgaris (snap bean) have been negatively impacted by leaf crumple disease caused by two whitefly-transmitted begomoviruses; cucurbit leaf crumple virus (CuLCrV) and sida golden mosaic Florida virus (SiGMFV), which often appear as a mixed infection in Georgia. Host resistance is the most economical management strategy against whitefly-transmitted viruses. Currently, information is not available with respect to resistance to these two viruses in commercial cultivars. In two field seasons (2018 and 2019), we screened Phaseolus sp. genotypes (n = 84 in 2018; n = 80 in 2019; most of the genotypes were common in both years with a few exceptions) for resistance against CuLCrV and/or SiGMFV. Twenty genotypes with high- to moderate-levels of resistance (disease severity ranging from 5-50%) to CuLCrV and/or SiGMFV were identified. Twenty-one genotypes were found to be highly susceptible with a disease severity of ≥66%. Adult whitefly counts differed significantly among snap bean genotypes for both years. The whole genome of these Phaseolus sp. (n=82) genotypes was sequenced and genetic variability among them was identified. Over 900 giga-base (Gb) of filtered data were generated and >88% of the resulting data were mapped to the reference genome, and SNP and Indel variants in Phaseolus genotypes were obtained. A total of 645,729 SNPs and 68,713 Indels including 30,169 insertions and 38,543 deletions were identified, which were distributed in 11 chromosomes with chromosome 02 harboring the maximum number of variants. These phenotypic and genotypic information will be helpful in genome-wide association studies that will aid in identifying genetic basis of resistance to these begomoviruses in Phaseolus sp.

To assess the genetic diversity of circulating dengue virus 2 in Senegal in 2018 we performed molecular characterization by complete genome sequencing and performing phylogenetic analysis. Sequenced strains belong to Cosmopolitan genotype of DENV-2 we observed intra-genotype variability leading to a divergence in two clades with differential geographic distribution. We report two variants namely; the “Northern variant” harbouring three nonsynonymous mutations (V1183M, R1405K, P2266T) located respectively on NS2A, NS2B and NS4A and the “Western variant” with two nonsynonymous mutations (V1185E, V3214E) located respectively in the NS2A gene and the NS5 gene. Findings calls for in depth in vitro and functional study to elucidate the impact of observed mutations on viral fitness, spread, epidemiology and disease outcome.

Background: SARS-CoV-2 infection has spread to over 200 countries since it was first reported in December of 2019. Significant country-specific variations in infection and mortality rate have been noted. Although country-specific differences in public health response have had a large impact on infection rate control, it is currently unclear as to whether evolution of the virus itself has also contributed to variations in infection and mortality rate. Previous studies on SARS-CoV-2 mutations were based on the analysis of ~ 160 SARS-CoV-2 sequences available until mid-February 2020.^{2, 3, 4, 5} By mid-April, > 550 SARS-CoV-2 sequences had been deposited in GenBank, and over 8,200 in the GISAID database. Methods: We performed a sequence analysis on 474 SARS-CoV-2 genomes submitted to GenBank up to April 11, 2020 by multiple alignment using Map to a Reference Assembly and Variants/SNP identification. The results were verified on a larger scale, 8,126 hCoV-19 (SARS-CoV-2) sequences from GISAID database. Results: We identified 5 recently emerged mutations in many isolates (up to 40%). Our analysis highlights 5 frequent new mutations that have emerged since late February 2020. These mutations are: one each missense (non-synonymous) mutation in orf1ab (C1059T), orf3 (G25563T) and orf8 (C27964T), one in 5’UTR (C241T), one in a non-coding region (G29553A). The final mutation (G29553A) was found to be almost exclusive to the US isolates. The first 3 mutations are non-synonymous, leading to amino acid substitutions in the viral protein sequence. Except for C241T, all the novel mutations identified are absent in the isolates from Italy and Spain in the SARS-CoV-2 genomes deposited in GenBank and GISAID by April 13, 2020. Conclusion: The results of current study indicate that new mutations are emerging as COVID-19 pandemic are spreading to different countries and that geography specific mutants may exist. The findings of current study lay the foundation for further investigation into the impact of SARS-CoV-2 mutations on disease incidence, severity, and host immune response. In addition, it may also provide insights into vaccine development and serological response detection for the virus.

Concatemeric viral DNA is packaged into Bacteriophage P22 procapsids via a headful packaging mechanism mediated by a molecular machine consisting of small (gp3) and large (gp2) terminase subunits. Although a negative stain reconstruction exists for the terminase holoenzyme, it is not clear how this complex binds dodecameric portal protein located at a 5-fold mismatch vertex. Herein, we describe new assemblies for the holoenzyme. Both native mass spectrometry and transmission electron microscopy reveal that the P22 terminase complex adopts three main assemblies, which include a nonameric S-terminase bound to two L-terminase 1(gp3)9:2(gp2), two nonameric S-terminase bound to five L-terminase 2(gp3)9:5(gp2), and three nonameric S-terminase bound to seven L-terminase 3(gp3)9:7(gp2). Native agarose gel electrophoresis shows that the terminase complex interacts with procapsid with mild crosslinking. These results herein illustrate the P22 terminase complex can adopt a variety of confirmations and assembly states.

The complete genomic sequence of a Cassava common mosaic virus Linggao isolate (CsCMV-LG) was determined from cassava (Manihot esculenta Crantz) with mild leafy mosaic symptom to no symptom in China. Excluding the poly(A) tail, the CsCMV-LG genome (GenBank accession No. MT038420) is 6374 nucleotides (nts) in length, with five major open reading frames encoding a 1450-amino acids (aa) RNA-dependent RNA polymerase (RdRp), three triple gene block (TGB) proteins (231-aa, 110-aa and 95-aa), and a 229-aa coat protein (CP). Phylogenetic analysis indicated that the complete genome of the CsCMV-LG is closely related to that of CsCMV-Brazilian which has been assigned to the genus Potexvirus, but the sequence identity shared only 88.0%. Notable, the mild CsCMV-LG isolate can also infect Nicotiana benthamiana in laboratory through rub inoculation causing mild vein yellowing at 15-day post inoculation. This is the first full-length genome sequence of a distinct isolate of Cassava common mosaic virus (CsCMV) infecting cassava in Hainan, China.

Apple chlorotic leaf spot virus (ACLSV) is a widespread, deleterious and the most damaging pathogen of fruit tree plants including domesticated apple (Malus domestica) ―a great threat to apple production worldwide. The positive-sense single-stranded RNA genome of ACLSV (7.5 Kbp) encodes three proteins: RNA polymerase (Rep), movement protein (MP) and coat protein (CP). RNA interference (RNAi)-mediated antiviral innate immunity is a key sequence-specific biological phenomenon in eukaryotes to control plant viruses. The aim of this study was to analyze apple (M.domestica) locus-derived microRNAs (mdm-miRNAs) with predicted potential for targeting the ACLSV +ssRNA-encoded mRNAs, using ‘four algorithms’ approach. The ultimate goal in this research is to mobilize the in silico endogenous predicted mdm-miRNAs to trigger RNAi catalytic pathway experimentally and generate apple tree varieties for evaluating potential antiviral resistance monitoring capability and capacity for ACLSV. Experimentally validated mature apple (M.domestica, 2n = 2X = 34) mdm-miRNAs (n = 322) were acquired from miRBase database and tested for alignment with the ACLSV genome. Of the 322 targeting mature locus-derived mdm-miRNAs investigated, nine apple mdm-miRNA homologs (mdm-miR395k, mdm-miR5225c and mdm-miR7121 (a, b, c, d, e, f, g, h) were predicted by all ‘four algorithms’. Only fifty eight mdm-miRNAs were predicted consensus binding sites by union of consensus between two algorithms. The miRanda, RNA22, TAPIR algorithms predicted binding of mdm-miR395k at unique nucleotide position 4691, as the most effectively interacting mdm-miRNAs in targeting the ORF1 sequence. In order to validate target prediction accuracy, whether the apple mdm-miRNAs might bind predicted ACLSV mRNA target(s), we created an integrated Circos plot. Genome-wide in-silico-predicted miRNA-mediated target gene regulatory network validated interactions that warrant in vivo analysis. The current work provides valuable evidence and biological material for generating ACLSV-resistant apple varieties.

Ebola virus (EBOV) is a zoonotic pathogen causing severe hemorrhagic fevers in humans and non-human primates with high case fatality rates. In recent years, the number and extent of outbreaks has increased, highlighting the importance of better understanding the molecular aspects of EBOV infection and host cell interactions to control this virus more efficiently. Many viruses, including EBOV, have been shown to recruit host proteins for different viral processes. Based on a genome-wide siRNA screen, we recently identified the cellular host factor carbamoyl-phosphate synthetase 2, aspartate transcarbamylase, and dihydroorotase (CAD) to be involved in EBOV RNA synthesis. However, mechanistic details of how this host factor plays a role in the EBOV life cycle remain elusive. In this study, we analyzed the functional and molecular interactions between EBOV and CAD. To this end, we used siRNA knockdowns in combination with various reverse-genetics based lifecycle-modelling systems and additionally performed co-immunoprecipitation and co immunofluorescence assays to investigate the influence of CAD on individual aspects of the EBOV life cycle and to characterize the interactions of CAD with viral proteins. Following this approach, we could demonstrate that CAD directly interacts with the EBOV nucleoprotein NP, and that NP is sufficient to recruit CAD into inclusion bodies dependent on the GLN-domain of CAD. Further, siRNA knockdown experiments indicated that CAD is important for both viral genome replication and transcription, while substrate rescue experiments showed that the function of CAD in pyrimidine synthesis is indeed required for those processes. Together this suggests that NP recruits CAD into inclusion bodies via its GLN domain in order to provide pyrimidines for EBOV genome replication and transcription. These results define a novel mechanism by which EBOV hijacks host cell pathways in order to facilitate genome replication and transcription, and provide further basis for the development of host directed broad spectrum antivirals.

Chicken infectious anemia (CIA) poses a significant threat to the chicken industry in China. De-spite its non-specific symptoms, the disease is often overlooked. This study aimed to conduct a comprehensive analysis of the etiology and pathology of CIA in Guangxi Province, China. Three strains of the chicken infectious anemia virus (CIAV) were isolated from liver samples of diseased 20-week-old chickens. The complete genomes of these strains were sequenced, and experiments on specific pathogen-free (SPF) chicks revealed that the GX21121 strain exhibited high virulence. Histopathological examination of the deceased chicks showed liver cell necrosis, fibrous-serous exudation, inflammatory cell infiltration, hemorrhage in liver tissues, as well as congestion in lung and renal tissues. Phylogenetic analysis of the genome revealed that the three strains had a close genetic relationship to the Heilongjiang wild-type (GenBank KY486144). The genetic evolu-tion of their VP1 genes indicated that all three CIAV isolates belonged to genotype IIIc. In sum-mary, this study demonstrated the genomic diversity of three CIAV strains in adult layer hens. The isolation and characterization of the GX21121 strain as a highly virulent isolate provide val-uable information for further investigations into the etiology, molecular epidemiology, and viral evolution of CIAV.

African swine fever (ASF) is one of the major threats to pig production, and real-time PCR (qPCR) protocols are integral part of ASF laboratory diagnosis. With the pandemic spread of ASF, commercial kits have risen on the market. In Germany, the kits have to go through an approval process and thus, general validation can be assumed. However, they were never compared to each other. In this study, 12 commercial PCR kits were compared to an OIE recommended method. Samples representing different matrices, genome loads, and genotypes were included in a panel that was tested under diagnostic conditions. The comparison included user-friendliness, internal controls, and the time required. All qPCRs were able to detect ASFV genome in different matrices across all genotypes and disease courses. With one exception, there were no significant differences when comparing the overall mean. The overall specificity was 100 % [95 % CI 87.66 - 100], and the sensitivity was between 95 % and 100 % [95 % CI 91.11 - 100]. As can be expected, variability concerned samples with low genome load. Concluding, all tests were fit for purpose. The test system can therefore be chosen based on compatibility and prioritization of the internal control system.

СrAss-like phages play an important role in maintaining ecological balance in the human intestine microbiome. However, their lifestyle and genetic diversity are still insufficiently studied. In this study, a novel CrAssE-Sib phage genome belonging to the epsilon сrAss-like phage genomes was found. Detailed analysis indicated that CrAssE-Sib encodes unusual proteins – DNA primase, virion RNA polymerase, prophage antirepressor, and transcriptional repressor, as well as reverse transcriptase (RT) and receptor binding protein (RBP) that are part of diversity-generating retroelement (DGR). Comparative analysis showed that all epsilon сrAss-like phages are divided into two putative genera, which were proposed to name Epsilonunovirus and Epsilonduovirus; CrAssE-Sib belongs to the first of them. RT from CrAssE-Sib and several Epsilonunoviruses contains a specific motif in its fourth domain that was not previously found in RTs from phage and bacterial DGRs. In addition, RBP from CrAssE-Sib and all Epsilonunoviruses has a unique structure. The presence of the conservative prophage repressor and anti–repressors that belong to the lysogenic-to-lytic cycle switches indicate that CrAssE-Sib and other Epsilonunoviruses could be temperate. Epsilon сrAss-like phage substantially differ from other crAss-like phages, including zeta сrAss-like phages. This fact indicates the need to isolate these phages into a separate family.

Tapping panel dryness (TPD) syndrome is a complex disease of Rubber tree (Hevea brasiliensis L.) which causes cessation of latex drainage upon tapping of rubber tree. Rubber tree virus (RTV1) was identified as a novel pathogen associated with rubber tree and a potential causal agent of TPD. RTV1 is a monopartite RNA virus that is linear, non-enveloped and has a single-stranded (ss) positive RNA genome of approximately 6081 nucleotides and is composed of two major open reading frames (ORFs), ORF1 (polyprotein), and ORF2 (movement protein. This study aimed to investigate the possibility of rubber genome encoded tree microRNAs (miRNAs) as novel therapeutic targets against RTV1 using in silico algorithms. Mature rubber tree miRNAs are retrieved from the miRBase database and are used for hybridization of RTV1 using five different five different computational algorithms including miRanda, RNA22, RNAhybrid and psRNATarget. A total of eleven common rubber tree miRNAs were identified based on consensus genomic positions. The consensus of four algorithms predicted the hybridization sites of hbr-miR396a and hbr-miR398 at common locus positions 6676, 1840 respectively. To validate the prediction, secondary structures of the consensual rubber tree miRNAs and free energy of duplex binding were calculated using the RNAfold and RNAcofold algorithms respectively. We created a plot between rubber tree miRNAs and RTV1 ORFs by using Circos algorithm. In this study, we predicted eleven consensual rubber tree miRNAs. Among these miRNAs, hbr-miR398 was identified as the most effectual miRNA that may target the ORF1 gene of the RTV1 genome. The predicted data will be important in the development of rubber trees resistant to RTV1.

Since mid-December of 2019, coronavirus disease 2019 (COVID-19) has been spreading from Wuhan, China. As of February 21, total 75,773 confirmed cases worldwide have spread to more than two dozen countries. Transmission of COVID-19 can occur early in the course of infection since SARS-CoV-2 viral loads in asymptomatic patients are similar to that in the symptomatic patients. Therefore, more sensitive diagnostic methods are needed to detect early phase of the infection to prevent secondary or tertiary spreads. Here, we compare the RT-PCR confirmatory test results using two different SARS-CoV-2 viral RNAs from two Korean COVID-19 confirmed cases.RT-PCR method targeting the RdRP gene, which was recommended by WHO guideline, was less sensitive than targeting N genes (as per CDC guideline). Because many countries follow the WHO guideline, our findings may contribute to the early diagnosis of COVID-19.

Wheat dwarf virus (WDV) causes an important vector transmitted virus disease, which leads to significant yield losses in barley production. Due to the fact, that at the moment no plant protection products are approved to combat the vector Psammotettix alienus and this disease cannot be controlled by chemical means, therefore the use of WDV resistant or tolerant genotypes is the most efficient method to control and reduce negative effects of WDV on barley growth and production. In this study, a set of 480 barley genotypes were screened to identify genotypic differences in response to WDV and five traits were assessed under infected and non-infected conditions. In total, 32 genotypes showed resistance or tolerance against WDV. Subsequently, the phenotypic data of 191 out of 480 genotypes combined with 34,408 single nucleotide polymorphisms (SNPs) in a genome wide association study to identify quantitative trait loci (QTLs) and markers linked to resistance/tolerance to WDV, using Tassel, GAPIT, and FARM CPU. In total, 1, 3, 2, 2 and 1 significantly associated markers on chromosomes 3H, 4H, 5H and 7H identified by all three methods for ELISA-60, relative performance of total grain weight, plant height, number of ears per plant and thousand grain weight, respectively.

Since 1998, when Jim van Etten’s team initiated its characterization, Paramecium bursaria Chlorella virus 1 (PBCV-1) had been the largest known DNA virus, both in terms particle size and genome complexity. In 2003, The Acanthamoeba-infecting Mimivirus unexpectedly superseded PBCV-1, opening the era of giant viruses, i.e. with virions large enough to be visible by light microscopy and genomes encoding more proteins than many bacteria. During the 15 following years, the isolation of many Mimivirus-relatives, have made the Mimiviridae one of the largest and most diverse family of eukaryotic viruses isolated from aquatic environments. Metagenomic studies keep suggesting that many more remain to be isolated. As Mimiviridae members are found to infect an increasing range of phytoplanckton species, their taxonomic position compared to the traditional Phycodnaviridae (i.e. etymologically “algal viruses”) became a source of confusion in the literature. Following a rapid history of the key discoveries that established the Mimiviridae family, we describe its current taxonomic structure and propose a set of operational criteria to help in the classification of future isolates.

The order Mononegavirales harbors numerous viruses of significant relevance for human health, including both established and emerging infections. Currently, vaccines are only available for a small subset of these viruses and antiviral therapies remain limited. Being obligate cellular parasites, viruses must utilize the cellular machinery for their replication and spread. Therefore, targeting cellular pathways used by viruses can provide novel therapeutic approaches. One of the key challenges confronted by both hosts and viruses alike is the successful folding and maturation of proteins. In cells, this task is faced by cellular molecular chaperones, a group of conserved and abundant proteins that oversee protein folding and help maintain protein homeostasis. In this review, we summarize the current knowledge of how the mononegavirales interact with cellular chaperones, highlight key gaps in our knowledge, and discuss the potential of chaperone inhibitors as antivirals.

We investigated the interaction between the insect-specific virus, Piura virus (PIUV) and the arbovirus Zika virus (ZIKV) in Aedes albopictus cells. We performed coinfection experiments in C6/36 cells. Piura virus (Cor 33 strain, Colombia) and ZIKV (PRVABC58 strain, Puerto Rico) were co-inoculated into C6/36 cells using two MOI combinations: 0.1 for both viruses and 1.0 for ZIKV, 0.1 for PIUV. Wells were infected in triplicate with either PIUV and ZIKV coinfection, ZIKV-only, or PIUV-only. Mock infected cells served as control wells. The cell suspension was collected daily through 7 days post-infection. Zika virus load was titrated by TCID50 on Vero 76 cells. The ZIKV-only infection and PIUV and ZIKV coinfection experiments were also quantified by RT-qPCR. We also investigated whether ZIKV interfered in the PIUV replication. PIUV suppressed the replication of ZIKV resulting in a 10,000-fold reduction in ZIKV titers within 3 days post-infection. PIUV viral loads were not reduced in the presence of ZIKV. We conclude that, when concurrently infected, PIUV suppresses ZIKV in C6/36 cells while ZIKV does not interfere in PIUV replication.

Flaviviruses are a group of positive sense single-stranded RNA viruses predominantly transmitted by arthropods (mainly mos-quitoes), that cause severe endemic infections and epidemics on a global scale. It represents a major cause of systemic morbidity and death that are expanding worldwide. Among this group, Dengue fever, West Nile virus, Yellow Fever, Japanese Encephalitis, and recently Zika virus have been linked to a spectrum of ocular manifestations. The latter encompass subconjunctival hemor-rhage and conjunctivitis, anterior and posterior uveitis (inclusive of vitritis, chorioretinitis, and retinal vasculitis), maculopathy, retinal hemorrhages, and optic neuritis. Clinical diagnosis of these infectious diseases is primarily based on epidemiological data, history, systemic symptoms and signs, and the pattern of ocular involvement. Diagnosis confirmation relies on laboratory testing, including RT-PCR and serological testing. Ocular involvement typically follows a self-limited course but can result in irreversible visual impairment. Effective treatment for flavivirus infections is currently unavailable. Prevention remains the mainstay for arthropod vector and zoonotic disease control. Effective vaccines are available only for Yellow Fever virus, Dengue virus and Japanese Encephalitis virus. This review comprehensively summarizes the current knowledge regarding the ophthalmic mani-festations of the foremost flavivirus-associated human diseases.

The phytophagous insect pests were vectors and could transmit the majority of the phytoviruses to their host plants. The orders of Hemiptera and Thysanoptera were the most common vectors of phytoviruses. The orders Orthoptera, Dermaptera, Coleoptera, Lepidoptera, Diptera, Thysanoptera, and Hemiptera were also the vectors of phytoviruses. Furthermore, aphids, whiteflies, cicadas, spittlebugs, leafhoppers, planthoppers, assassin bugs, plant bugs, stink bugs, lygaeid bugs, and thrips were among the most phytophagous insects that vector and transmit phytoviruses to healthy plants. The occurrence of a single species of these phytophagous insects resulted in one or more phytoviruses in general, and the Hemipteran order, in particular, vectored a lot of phytoviruses species. This review manuscript is focused on vectors of phytoviruses, techniques for their detection, and future directions. It will play a vital role in exploring scientific information concerning the interactions of phytoviruses and vector insects, the effect of phytoviruses on host behavior, mediators of phytoviruses transmission, persistent phytoviruses, some other insect vectors of the phytopathogen, mechanisms of host plant resistance against phytoviruses, and techniques of phytoviruses detection, as well as some important points to be considered in the future sustainably.

This article challenges the notion of the randomness of mutations in eukaryotic cells by unveiling stress-induced human non-random genome editing mechanisms. To account for the existence of such mechanisms, I have developed molecular concepts of the cell environment and cell environmental stressors and, making use of a large quantity of published data, hypothesized the origin of some crucial biological leaps along the evolutionary path of life on Earth under the pressure of natural selection, in particular, 1) virus-cell mating as a primordial form of sexual recombination and symbiosis; 2) Lamarckian CRISPR-Cas systems; 3) eukaryotic gene development; 4) antiviral activity of retrotransposon-guided mutagenic enzymes and finally; 5) the exaptation of antiviral mutagenic mechanisms to stress-induced genome editing mechanisms directed at “hypertranscribed” endogenous genes. Genes transcribed at their maximum rate (hypertranscribed), yet still unable to meet new chronic environmental demands generated by “pollution”, are inadequate and generate more and more intronic retrotransposon transcripts. In this scenario, RNA-guided mutagenic enzymes (e.g. AID/APOBECs), which have been shown to bind to retrotransposon RNA-repetitive sequences, would be surgically targeted by intronic retrotransposons on opened chromatin regions of the same “hypertranscribed” genes. RNA-guided mutagenic enzymes may therefore “Lamarkianly” generate single nucleotide polymorphisms (SNP) and copy number variations (CNV), as well as transposon transposition and chromosomal translocations in the restricted areas of hyperfunctional and inadequate genes, leaving intact the rest of the genome. CNV and SNP of hypertranscribed genes may allow cells to surgically explore a new fitness scenario, which increases their adaptability to stressful environmental conditions. Like the mechanisms of immunoglobulin somatic hypermutation, non-random genome editing mechanisms may generate several cell mutants, and those codifying for the most environmentally-adequate proteins would have a survival advantage and would therefore be Darwinianly selected. Non-random genome editing mechanisms represent a link between environmental changes and biological novelty and plasticity, and provide a molecular basis to reconcile gene-centered and “ecological” views of evolution.

Flaviviruses cause a significant amount of mortality and morbidity, especially in the area where they are endemic. A recent example is the outbreak of Zika virus though out the world. Development of antiviral drugs against different viral targets is as important as development of vaccine. During viral replication, the flavivirus genome is translated as a single polyprotein precursor, which must be cleaved into individual proteins by a complex of the viral protease, NS3, and its cofactor, NS2B. Flavivirus protease is the most attractive target for development of therapeutic antivirals because it is essential for processing of viral polyprotein precursor and generation of functional viral proteins. In this review, we have summarized recent development in drug discovery targeting NS3-NS2B protease of flaviviruses, especially Zika, dengue and West Nile virus.

Long noncoding RNAs (lncRNAs) of virus origin accumulate in cells infected by many positive strand (+) RNA viruses to bolster viral infectivity. Their biogenesis mostly utilizes exoribonucleases of host cells that degrade viral genomic or subgenomic RNAs in the 5’-to-3’ direction until being stalled by well-defined RNA structures. Here we report a viral lncRNA that is produced by a novel replication-dependent mechanism. This lncRNA corresponds to the last 283 nucleotides of the turnip crinkle virus (TCV) genome, hence is designated tiny TCV subgenomic RNA (ttsgR). ttsgR accumulated to high levels in TCV-infected Nicotiana benthamiana cells when the TCV-encoded RNA-dependent RNA polymerase (RdRp), also known as p88, was overexpressed. Both (+) and (-) strand forms of ttsgR were produced in these cells in a manner dependent on the RdRp functionality. Strikingly, templates as short as ttsgR itself were sufficient to program ttsgR amplification, as long as the TCV-encoded replication proteins, p28 and p88, were provided in trans. Consistent with its replicational origin, ttsgR accumulation required a 5’ terminal G₃(A/U)₄ motif shown by others to be crucial for the replication of a TCV satellite RNA. More importantly, introducing a new G₃(A/U)₄ motif elsewhere in the TCV genome was alone sufficient to cause the emergence of another lncRNA. Collectively our results unveil a replication-dependent mechanism for the biogenesis of viral lncRNAs, thus suggesting that multiple mechanisms, individually or in combination, may be responsible for viral lncRNA production.

The influenza virus has been the primary cause of the pandemic, posing a constant threat to human society. Due to its genetic evolution and continuous outbreak, antiviral research currently focuses on exploring a novel lead agent. A comprehensive antiviral screening discovered a marine bacterium whose extract exerted excellent efficacy against influenza viruses. Parerythrobacter sp. M20A3S10, a novel strain under the family Erythrobacteraceae, could produce carotenoids exhibiting antiviral and anticancer activity by enhancing the cellular immune system. Post-treatment of M20A3S10 extract showed outstanding therapeutic indexes: against influenza virus A/PR8 (H1N1) [selectivity index (SI) = 24.0], A/Wisconsin/15/2009 (H3N2) (SI = 30.1) and B/Florida/78/2015 (SI = 38.2). Comparably, the effectiveness was demonstrated against Zika virus (ZIKV) and dengue virus type 2 (DENV2) with an SI of 22.5 and 24.1, respectively, namely broad-spectrum activity. Of note, the antiviral responses resulted from the common replication mechanism between IAV, ZIKV, and DENV2. The stimulation of apoptosis-mediated cellular immunity prevented the viral release and protected the host, suggesting that switching from necroptosis to apoptosis is a novel antiviral target. Although the specific compound affecting the antiviral activity was not identified, its promising efficacy with broad activity will contribute to developing a strategy for preventing future pandemics.

Zika virus (ZIKV) is a widespread mosquito-borne pathogen. Phylogenetically, two lineages of the ZIKV are distinguished: African and Asian-American. The latter became the cause of the 2015-2016 pandemic with severe defeat to newborns. In West African countries the African lineage has been found, but there is evidence of the emergence of Asian-American lineage in Cape Verde and Angola. This highlights the need not only to monitor the ZIKV, but also to sequence the isolates. In this article, we present a case report of Zika fever in a pregnant woman from Guinea, identified in 2018. Viral RNA was detected by qRT-PCR in serum sample. In addition, seroconversion of anti-Zika IgM and IgG antibodies was detected in repeated blood samples. Subsequently, the virus was isolated in C6/36 cell line. The detected ZIKV belonged to the African lineage, the Nigerian sublineage. The strains with the closest sequences were isolated from mosquitoes in Senegal in 2011 and 2015. In addition, we conducted serological screening of 116 blood samples collected from patients presenting to the hospital of Faranah with fevers during the period 2018-2021. As a result, it was found that IgM-positive patients occurred each year, seroprevalence varied between 5.6% and 17.1%.

A pandemic happens when a novel influenza A virus is able to infect and transmit efficiently to a new, distinct host species. Although the exact timing of pandemics is uncertain, it is known that both viral and host factors play a role in their emergence. Species-specific interactions between the virus and the host cell determine the virus tropism. These include binding and entering cells, replicating the viral RNA genome within the host cell nucleus, assembling, maturing, and releasing the virus to neighbouring cells, tissues, or organs before transmitting it between individuals. Influenza has a vast and antigenically varied reservoir. In wild aquatic birds, the infection is typically asymptomatic. Avian influenza virus (AIV) can cross into new species, and occasionally, it can acquire the ability to transmit from human to human. A pandemic might occur if a new influenza virus acquires enough adaptive mutations to maintain transmission between people. This review highlights the key determinants AIV must achieve to initiate a human pandemic and describes how AIV mutates to establish tropism and stable human adaptation. Understanding the tropism of AIV may be crucial in preventing virus transmission in humans and may help design vaccines, antivirals and therapeutic agents against the virus.

Marburg virus (MARV) is a lipid-enveloped negative sense single stranded RNA virus, which can cause a deadly hemorrhagic fever. MARV encodes seven proteins, including VP40 (mVP40), a matrix protein that interacts with the cytoplasmic leaflet of the host cell plasma membrane. VP40 traffics to the plasma membrane inner leaflet, where it assembles to facilitate the budding of viral particles. VP40 is a multifunctional protein that interacts with several host proteins and lipids to complete the viral replication cycle, but many of these host-interactions remain unknown or are poorly characterized. In this study, we investigated the role of a hydrophobic loop region in the carboxy-terminal domain (CTD) of mVP40 that shares sequence similarity with the CTD of Ebola virus VP40 (eVP40). These conserved hydrophobic residues in eVP40 have been previously shown to be critical to plasma membrane localization and membrane insertion. An array of cellular experiments and confirmatory in vitro work strongly suggests proper orientation and hydrophobic residues (Phe281, Leu283, and Phe286) in the mVP40 CTD are critical to plasma membrane localization. In line with the different functions proposed for eVP40 and mVP40 CTD hydrophobic residues, molecular dynamics simulations demonstrate large flexibility of residues in the EBOV CTD whereas conserved mVP40 hydrophobic residues are more restricted in their flexibility. This study sheds further light on important amino acids and structural features in mVP40 required for its plasma membrane localization as well as differences in the functional role of CTD amino acids in eVP40 and mVP40.

This study reports the design of a dielectric resonator (DR) metasurface-based terahertz biosensor for rapid and accurate detection of different kinds of viruses (H1N1, SARA-COV-2, etc.). The characterization of the sensor is done by analyzing its absorbance properties with and without the presence of the H1N1 virus layer of different concentrations and electrical properties in the frequency range of 2.4 THz to 3 THz. A full-wave EM model of the sensor is designed using CST MWS software. The geometrical parameters of the proposed biosensor, as well as its dielectric constant of the virus swab, are varied to achieve good performance with an absorption level close to 1 (100%). A significant change in the resonating pick-up frequency owing to the variation in the effective refractive index of the realized sensor ensures the detection and classification of the different concentrations of the same or different viruses. The presented design could be used for the rapid detection of viruses with the added advantages of contactless, label-free, and accurate identification of different concentrations of viruses.

Dengue has long been a serious health burden to the global community, especially for those living in the tropics. In spite of the availability of vaccines, effective treatment for the infection is still needed and currently remained absent. In the present study, antiviral properties of the KSF 103 ME which consisted of a number of potential antiviral compounds were investigated against DENV-2. The effects of this extract against DENV-2 replication were determined using the qRT-PCR. Findings from the study suggested that the KSF 103 ME showed maximum inhibitory properties toward the virus during the virus entry stage at concentrations of more than 12.5 µg/mL. Minimal antiviral activities were observed at other virus replication stages; adsorption (42% reduction at 50 µg/mL), post-adsorption (67.6% reduction at 50 µg/mL), prophylactic treatment (68.4% and 87.7% reductions at 50 µg/mL and 25 µg/mL, respectively) and direct virucidal assay (48% and 56.8% reductions at 50 µg/mL and 25 µg/mL, respectively. The KSF 103 ME inhibited dengue virus repication with an IC50 value of 20.3 µg/mL and SI value of 38.9. The KSF 103 ME showed potent antiviral properties against DENV during the entry stage. Further studies will be needed to deduce the antiviral mechanisms of the KSF 103 ME against DENV.

Survival following Ebola virus (EBOV) infection correlates with the ability to mount an early and robust interferon (IFN) response. The host IFN-induced proteins that contribute to controlling EBOV replication are not fully known. Among the top genes with the strongest early increases in expression after infection in vivo is IFN-induced HERC5. Using a transcription- and replication-competent VLP system, we showed that HERC5 inhibits EBOV virus-like particle (VLP) replication by depleting EBOV mRNAs. The HERC5 RCC1-like domain was necessary and sufficient for this inhibition and did not require zinc finger antiviral protein (ZAP). Moreover, we showed that EBOV (Zaire) glycoprotein (GP) but not Marburg virus GP antagonized HERC5 early during infection. Our data identifies a novel ‘protagonist-antagonistic’ relationship between HERC5 and GP in the early stages of EBOV infection that could be exploited for the development of novel antiviral therapeutics.

The major arboviruses belong mainly to the families Bunyaviridae, Togaviridae, and Flaviviridae amongst which chikungunya virus and dengue virus have emerged as a global public health problem. The main objective of the study was to develop a specific, sensitive, and cost-effective molecular multiplex RT-PCR and RT-qPCR assay for the rapid and simultaneous detection of CHIKV and the four serotypes of DENV for arbovirus surveillance. Specific primers of all virus were designed, one step multiplex RT-PCR (mRT-PCR) and RT-qPCR (mRT-qPCR) was developed using reference strains of CHIKV and DENV serotypes. The specificity of the test for all the viruses was confirmed by sequencing. The standard curves showed a high correlation coefficient, R2= 0.99, for DENV-2 and DENV-3; R2= 0.98, for DENV-4 and CHIKV; R2= 0.93, for DENV-1. The limits of detection were calculated to be 10-2 copies/µL for all viruses. The specificity and sensitivity of the newly developed mRT-PCR and mRT-qPCR were validated using positive serum samples collected in India and Burkina Faso. The sensitivity of mRT-PCR and mRT-qPCR are 91%, and 100% respectively. The specificity of both assays was 100% specific. mRT-PCR and mRT-qPCR assays are low cost and a combination of both will be a useful tool for arbovirus surveillance.

Zika virus (ZIKV) is a mosquito-borne flavivirus, and its infection may cause severe neurodegenerative diseases. The outbreak of ZIKV in 2015 in South American has caused severe human congenital and neurologic disorders. Thus, it is vitally important to figure out inner mechanism of ZIKV infection. Here, our data suggested that the ubiquitin-specific peptidase 38 (USP38) played an important role in host resistance to ZIKV infection, during which ZIKV infection did not affect USP38 expression. Mechanistically, USP38 bound to ZIKV envelope (E) protein through its C-terminal domain and attenuated its K48-linked and K63-linked polyubiquitination, thereby repressed the infection of ZIKV. In addition, we found that the deubiquitinase activity of USP38 was essential to inhibit ZIKV infection, and the mutant that lacked the deubiquitinase activity of USP38 lost ability to inhibit the infection. In conclusion, we found a novel host protein USP38 against ZIKV infection, and this may represent a potential therapeutic target for the treatment and prevention of ZIKV infection.

Many positive sense RNA viruses, especially those infecting plants, are known to experience stringent, stochastic population bottlenecks inside the cells they invade, but exactly how and why these populations become bottlenecked are unclear. A model proposed ten years ago advocates that such bottlenecks are evolutionarily favored because they cause the isolation of individual viral variants in separate cells. Such isolation in turn allows the viral variants to manifest the phenotypic differences they encode. Recently published observations lend mechanistic support to this model, and prompt us to refine the model with novel molecular details. The refined model, designated Bottleneck, Isolate, Amplify, Select (BIAS), postulates that these viruses impose population bottlenecks on themselves by encoding bottleneck-enforcing proteins (BNEPs) that function in a concentration-dependent manner. In cells simultaneously invaded by numerous virions of the same virus, BNEPs reach the bottleneck-ready concentration sufficiently early to arrest nearly all internalized viral genomes. As a result, very few (as few as one) viral genomes stochastically escape to initiate reproduction. Repetition of this process in successively infected cells isolate viral genomes with different mutations in separate cells. This isolation prevents mutant viruses encoding defective viral proteins from hitchhiking on sister genome-encoded products, leading to the swift purging of such mutants. Importantly, genome isolation also ensures viral genomes harboring beneficial mutations accrue the cognate benefit exclusively to themselves, leading to the fixation of such beneficial mutations. Further interrogation of the BIAS hypothesis promises to deepen our understanding of virus evolution, and inspire new solutions to virus disease mitigation.

From the first isolation of the cystovirus bacteriophage Φ6 from Pseudomonas syringae 50 years ago, we have progressed to a better understanding of the structure and transformations of the many parts of the virion. The three-layered virion encapsulating the tripartite double stranded RNA (dsRNA) genome, breaches the cell envelope on infection, generates its own transcripts, and coopts the bacterial machinery to produce its proteins. The generation of new virions starts with a procapsid with a contracted shape, followed by packaging single stranded RNA segments with concurrent expansion of the capsid, and finally replication to reconstitute the dsRNA genome. The outer two layers are then added, and the fully formed virions released by cell lysis. Most of the procapsid structure composed of the proteins P1, P2, P4 and P7 is now known, as well as its transformations to the mature, packaged nucleocapsid. The outer two layers are less well studied. One additional study investigated the binding of the host protein YajQ to the infecting nucleocapsid, where it enhances the transcription of the large RNA segment that codes for the capsid proteins. Finally, we relate the structural aspects of bacteriophage Φ6 top those of other dsRNA viruses, noting the similarities and differences.

Understanding biological mechanisms that regulate emergence of viral diseases, in particular those events engaging cross-species pathogens spillover, are becoming increasingly important in Virology. Species barrier jumping has been extensively studied in animal viruses, and the critical role of a suitable intermediate host in animal viruses-generated human pandemics is highly topical. However, studies on host jumping involving plant viruses have been focused on shifting intra-species, leaving aside the putative role of “bridge hosts” in facilitating interspecies crossing. Here, we take advantage of several VPg mutants, derived from a chimeric construct of the potyvirus Plum pox virus (PPV), analysing its differential behaviour in three herbaceous species. Our results showed that two VPg mutations in a Nicotiana clevelandii-adapted virus, emerged during adaptation to the bridge-host Arabidopsis thaliana, drastically prompted partial adaptation to Chenopodium foetidum. Although, both changes are expected to facilitate productive interactions with eIF(iso)4E, polymorphims detected in PPV VPg and the three eIF(iso)4E studied, extrapolated to a recent VPg:eIF4E structural model, suggested that two adaptation ways can be operating. Remarkably, we found that VPg mutations driving host-range expansion in two non-related species, not only are not associated with cost trade-off constraints in the original host, but also improve fitness on it.

Diseases caused by arboviruses are on the increase worldwide. In addition to arthropod bites, most arboviruses can be transmitted via accessory routes. Products of human origin (labile blood products, solid organs, hematopoietic stem cells, tissues) present a risk of contamination for the recipient if the donation is made when the donor is viremic. This narrative review describes the risks of acquiring certain arboviral diseases from human products, mainly solid organs and hematopoietic stem cells, in the French context. Mainland France and its overseas territories are exposed to a complex array of imported and endemic arboviruses, which differ according to their respective location. The main risks considered in this study are infections by West Nile virus, dengue virus and tick-borne encephalitis virus. The ancillary risks represented by Usutu virus infection, chikungunya and Zika are also addressed more briefly. For each disease, the guidelines issued by the French High Council of Public Health, which is responsible for issuing guidelines to mitigate the risks associated with products of human origin and for supporting public health policy decisions, are briefly outlined. The aim of this review is also to contribute to the standardization of recommendations at international level in areas with the same viral epidemiology.

Due to the fact that to date, the question of the origin of SARS-CoV-2 has not been resolved yet, the author analyzed the main advances in the development of genetic engineering of viruses that took place before the onset of the COVID-19 pandemic. The first artificial genetically modified viruses could appear in nature in the mid-1950s. The technique of nucleic acid hybridization was developed by the end-1960s. In the late 1970s, a method called the "reverse genetics" emerged to synthesize RNA and DNA molecules. In the early 1980-s, it became possible to combine the genes of different viruses and insert the genes of one virus into the genome of another virus. Since that time, the production of vector vaccines began. Currently, by modern technologies one can assemble any virus based on the nucleotide sequence available in the virus database or designed by a computer as a virtual model.Scientists around the world are invited to answer the call of Neil Harrison and Jeffrey Sachs of Columbia University, for a thorough and independent investigation into the origin of SARS-CoV-2. Only a full understanding of the origin of the new virus can minimize the likelihood of a similar pandemic in the future.

We present the detailed calculations of social distancing requirement. A comparative study of the growth pattern and death tolls in different communities indicates that the growth pattern of infected patients and death rate follow the similar distribution with different parametrizations. Every distribution follows an exponential growth pattern curve, like other microbes, then reaches the saturation point an d eventually decay s However, the argument for the exponential function depends on several parameters unbeknownst, as of yet. However, the slope varies different ial ly for various epicenter s and seems to have a relationship with parameters such as accessibi lity to healthcare facilities, pre existing medical conditions socio economic conditions and lifestyle. The mismatch of the growth pattern is also linked with the impact of various other factors and a premature interpretation of limit ed data. Novel behavi or of the virus brought many surprises, opened up new venues for medical research, and the need for the more detailed study of pathogens in the light of the interaction of RNA and DNA The adaptability to diverse ecological condition s and the relevant modification in the structure is also worth investigation The genetic modification can be studied using quantum mechanical probabilistic approach.

Many protein expression systems are primary utilised to produce a single, specific recombinant protein. In contrast, most biological processes such as virus assembly rely upon a complex of several interacting proteins rather than the activity of a sole protein. The high complexity of the baculovirus genome, coupled with a multiphase replication cycle incorporating distinct transcriptional steps, made it the ideal system to manipulate for high-level expression of a single or co-expression of multiple foreign proteins within a single cell. We have developed and utilised a series of recombinant baculovirus systems to unravel the sequential assembly process of a complex non-enveloped model virus, Bluetongue virus (BTV). The high protein yields expressed by the baculovirus system not only facilitated structure-function analysis of each viral proteins but were also advantageous to crystallography studies and supported the first atomic level resolution of a recombinant viral protein, the major BTV capsid protein. Further, the formation of recombinant double-shelled virus-like particles (VLPs) provided insights into the structure-function relationships among the four major structural proteins of the BTV whilst also representing a potential candidate for a viral vaccine. The baculovirus multi-gene expression system facilitated the study of structurally complex viruses (both non-enveloped and enveloped viruses) and heralded in a new generation of viral vaccines.

Tick-borne encephalitis virus (TBEV) is one of the most threatening pathogens which affects the human central nervous system (CNS). TBEV circulates widely in Northern Eurasia. According to ECDC the number of TBE cases increase annually. There is no specific treatment for the TBEV infection, thus vaccination is the main preventive measure. Despite the existence of several inactivated vaccines currently being licensed, the development of new TBEV vaccines remains a leading priority in countries endemic to this pathogen. Here we report new recombinant virus made by infectious subgenomic amplicon (ISA) approach using TBEV and yellow fever virus vaccine strain (YF17DD-UN) as a genetic backbone. The recombinant virus is capable of effective replication in mammalian cells and induce TBEV-neutralizing antibodies in mice. Unlike the original vector based on the yellow fever vaccine strain chimeric virus became neuroinvasive in doses of 107-106 PFU and can be used as a model of Flavivirus neuroinvasiveness, neurotropism and neurovirulence. These properties of hybrid structures are the main factors limiting their practical use as vaccines platforms.

It is important to be able to detect and differentiate between distinct porcine enteric coronaviruses that can cause similar diseases. However, the existence of naturally occurring recombinant coronaviruses such as swine enteric coronavirus (SeCoV) can give misleading results with currently used diagnostic methods. Therefore, we have developed and validated three duplex real-time quantitative RT-PCR assays for the simultaneous detection of, and differentiation between, porcine epidemic diarrhea virus (PEDV) and SeCoV. Transmissible gastroenteritis virus (TGEV) is also detected by two out of these three assays. In addition, a novel triplex assay was set up that was able to detect and differentiate between these alphacoronaviruses and the porcine deltacoronavirus (PDCoV). The validated assays have low limits of detection, close to 100% efficiency and were able to correctly identify the presence of PEDV and SeCoV in 55 field samples, while 20 samples of other pathogens did not give a positive result. Implementing one or more of these multiplex assays into the routine diagnostic surveillance for PEDV will ensure that the presence of SeCoV, TGEV and PDCoV will not go unnoticed.

The induction of acoustic-mechanical oscillations to virus particles by illuminating them with microwave signals is analyzed theoretically. Assuming the virus particle being of spherical shape, its capsid consisting primarily of glycoproteins, a viscous fluid model is adopted while the outside medium of the sphere is taken to be ideal fluid. The electrical charge distribution of virus particle is assumed to be spherically symmetric with a variation along the radius. The generated acoustic-mechanical oscillations are computed by solving a boundary value problem analytically, making use of the Green’s function approach. Resonance conditions to achieve maximum energy transfer from microwave radiation to acoustic oscillation to the particle is investigated. Estimation of the feasibility of the technique to compete virus epidemics either for sterilization of spaces and/or use for future therapeutic applications is examined briefly.

Evolution remains an incessant process in viruses, allowing them to elude host immune response and induce severe diseases, impacting the diagnostic and vaccine effectiveness. Predicting emerging viral genomes is crucial, particularly in diseases like dengue, where viruses disrupt host cells, leading to fatal outcomes. Deep learning has been applied to predict dengue fever cases; there has been relatively less emphasis on its significance in forecasting emerging Dengue Virus (DENV) serotype. While Recurrent Neural Networks (RNN) were originally designed for modeling temporal sequences, our proposed DL-DVE generative and classification model, trained on complete genome data of DENV, transcends traditional approaches by learning semantic relationships between nucleotides in a continuous vector space instead of representing contextual meaning of nucleotide characters. Leveraging 2000 publicly available DENV complete genome sequences, our Long Short-Term Memory (LSTM) based generative and Feedforward Neural Network (FNN) based classification DL-DVE model showcases proficiency in learning intricate patterns and generating sequences for emerging serotype of DENV. The generative model showed accuracy of 93% and the classification model provided insight into the specific serotype label, corroborated by BLAST search verification. Evaluation metrics such as ROC-AUC value 0.818, accuracy, precision, recall and F1 score all to be around 99.00%, demonstrated the classification model’s reliability.  Our model classified the generated sequences as DENV-4, exhibiting 65.99% similarity to DENV-4 and around 63-65% similarity with other serotypes, indicating notable distinction from other serotypes. Moreover, the intra-serotype divergence of sequences with a minimum 90% similarity underscored their uniqueness. We analyzed the conserved motifs in the genome through MEME Suite (version 5.5.5). Our research strives to contribute to the ongoing fight against the Dengue virus by offering predictive insights into its genomic evolution. Looking ahead, proactive predictive modeling before mutations occur holds potential for guiding vaccine design and diagnostic kit development.

Medicinal plants are being tested as options to prevent infectious diseases in many countries. Baccharis crispa Spreng. (Asteraceae), is a native medicinal species widely used throughout South America. Our objective was to evaluate the antiviral activity of four wild populations of B. crispa from the province of Córdoba (Argentina) and determine if there is variability between them. The cytotoxicity of the extracts (chlorofom, ethanol and aquose) was evaluated by the neutral red uptake method. Using the plaque-forming unit reduction assay, virucidal and antiviral activity against Herpes Simplex type 1 and Chikungunya viruses were tested. Phytochemical screening of each extract was also performed. Puesto Pedernera (PP) population showed the best antiviral and virucidal effect, standing out the ethanolic extract as the least toxic and with the best inhibitory activity against both viral models. Villa del Parque (VP) population was inactive, regardless of the extract and the virus tested. The results revealed that extracts bioactivities vary significantly depending on the geographic area of collection, with PP and VP populations showing the most significant variability, not only in activity but also in chemical composition. These findings support the potential use of extracts as a source of therapeutic agents against different viruses.

Tilapia lake virus (TiLV) is the main tilapia-infecting virus worldwide, causing serious economic losses. However, there is no vaccine for this viral disease. Here, TiLV ORF10 (TiLV-ORF10) encoding a protein with abundant epitopes was constructed into the eukaryotic expression vector pcDNA3.1, and used to evaluate the immune protective effects in Nile tilapia (Oreochromis niloticus). RT-PCR and western blot analyses confirmed vaccine plasmid expression in tilapia muscle tissues. Moreover, the transcription levels of immunoglobulin M, toll-like receptor 2, myeloid differentiation factor 88, interleukin 8, tumor necrosis factor alpha, gamma-IFN, and nuclear factor κB immune-related genes were statistically significantly upregulated in the spleen, liver, and kidney of vaccinated tilapias (P < 0.05). TiLV challenge experiments showed that relative percent survival (RPS) was significantly enhanced in fish by this DNA vaccine. Moreover, RPS was enhanced further when using a higher amount of the DNA vaccine (85.72% RPS at a DNA dose of 45 μg pcDNA3.1–ORF10). Vaccination with pcDNA3.1–ORF10 significantly reduced virus replication, as evidenced by the low amount of virus in the spleen, liver, and kidney of vaccinated tilapias after TiLV challenge. Thus, pcDNA3.1–ORF10 could induce protective immunity in tilapia and may be a potential vaccine candidate for controlling diseases caused by TiLV.

Arthropod-borne viruses belonging to the flavivirus genus possess an enormous relevance in public health. Neotropical non-human primates (NPs) have been proposed to be infected more frequently with flaviviruses due to their arboreal and diurnal habits, their genetic similarity to humans and their relative closeness to humans. However, the only known flavivirus in America that is maintained by sylvatic cycles involving NPs is Yellow Fever virus (YFV), and the NPs role as potential hosts of flaviviruses is still unknown. Here, we examined flavivirus exposure in 86 free range and captive NPs of Costa Rica to evaluate their involvement in flavivirus transmission cycles and their potential as flavivirus hosts. We used a highly-specific micro plaque reduction neutralization test (micro-PRNT) to determine the presence of antibodies against YFV, Dengue virus 1-4 (DENV), Zika virus, West Nile Virus (WNV) and Saint Louis Encephalitis virus (SLEV). We found evidence of seropositive NPs to DENV-1 8.2% (homotypic –3/86, heterotypic – 4/86), SLEV 15.1% (homotypic – 10/86, heterotypic – 2/86), WNV 2.3% (homotypic – 2/86) and 8.1% (7/86) undetermined Flavivirus species. No antibodies against YFV or ZIKV were found. This work provides compelling serological evidence of exposure in NPs of flaviviruses associated with urban cycles, i.e. DENV, and confirms decades of circulation of SLEV in the same environments. Also, the range of years of sampling and the socioeconomic region was statistically significant for the presence of Dengue and Flavivirus undetermined seropositive individuals, respectively. Both the years and socioeconomic regions with greater seroprevalence coincide with the years and socioeconomic regions with high numbers of Dengue human cases for the country. Our work suggests bidirectional? circulation of different flaviviruses between humans and wildlife with public health importance and underscores the necessity of further surveillance for flaviviruses in the humans/wildlife interface in Central America.

A striking aspect of COVID-19 is the difference in the outcome of the infection between different countries, and different ethnic groups within one country. We surveyed the literature on SARS-CoV-2 complemented with comparative publications on SARS-CoV and other coronaviruses to capture the current understanding of virus – host interactions including virus subtypes, transmission, zoonotic aspects, and potential host determinants.

This paper describes new horizons in the diversity and taxonomy of negev-like viruses encoding the membrane-embedded SP24 protein. First, our data extend the known host range of SP24-encoding negev-like viruses to include brown algae, fungi, green plants, the phylum Entoprocta, the phylum Mollusca, and vertebrates. Second, our phylogenetic analysis suggests that the evolution of the SP24 gene family may have involved frequent events of inter-order virus genome shuffling. Third, the identification of 2-3 copies of SP24 protein genes in some virus RNAs shows that virus genomes may have acquired additional SP24 genes during the evolutionary process due to duplications or new acquisition steps. Forth, the broad host specificity of some SP24-encoded viruses may be related to an important adaptive role of SP24. Fifth, insect and nematode genomes may acquire viral SP24 genes by putative horizontal transfer from negev-like viruses known to infect species of both taxa.

Infection with Ebola virus (EBOV) is responsible for haemorrhagic fever in humans with a high mortality rate. Combined efforts of prevention and therapeutic intervention are required to tackle highly variable RNA viruses, whose infections often lead to outbreaks. Here, we have screened the 2P2I3D chemical library using a nanoluc-based protein complementation assay (NPCA) and isolated two compounds disrupting the interaction of the EBOV protein fragment VP35IID with the N terminus of the dsRNA-binding proteins PKR and PACT, involved in IFN response and/or intrinsic immunity, respectively. The two compounds inhibited EBOV infection in cell culture as well as infection by measles virus (MV) independently of IFN induction. Consequently, we propose the compounds are antiviral by restoring intrinsic immunity driven by PACT. Given that PACT is highly conserved across mammals, we support further testing of the compounds in other species, as well as against further negative sense RNA viruses.

Herpes simplex virus 1 (HSV-1) expresses a large number of miRNAs, and their function is still not completely understood. In addition, HSV-1 has been found to deregulate host miRNAs, which adds to the complexity of regulation of efficient virus replication. In this study, we comprehen-sively addressed the deregulation of host miRNAs by massive-parallel sequencing. We found that only miRNAs expressed from a single cluster, miR-183/96/182 are reproducibly deregulated dur-ing productive infection. These miRNAs are predicted to regulate a great number of potential tar-gets involved in different cellular processes and have only 33 shared targets. Among these, mem-bers of the FoxO family of proteins were identified as potential targets for all three miRNAs. However, our study shows that the upregulated miRNAs do not affect the expression of FoxO proteins, moreover these proteins were upregulated in HSV-1 infection. Furthermore, we show that the individual FoxO proteins are not required for efficient HSV-1 replication. Taken together, our results indicate a complex and redundant response of infected cells to the virus infection that is efficiently inhibited by the virus.

Background: Every year, millions of people are hospitalized, and thousands die from influenza A virus (FLUAV) infection. Most cases of hospitalizations and death occur among elderly. Many of these elderly patients are reliant on medical treatment of underlying chronic diseases, such as arthritis, diabetes, and hypertension. We hypothesized that the commonly prescribed medicines for treatment of underlying chronic diseases can affect host responses to FLUAV infection, and thus contribute to morbidity and mortality associated with influenza. Therefore, the aim of this study was to examine whether commonly prescribed medicines could affect host responses to virus infection in vitro. Methods: We first identified 45 active compounds of medicines commonly prescribed in Central Norway. Then we constructed a drug-target interaction network and identified potential implication of these interactions for FLUAV-host cell interplay. Finally, we tested the effect of 45 drugs on viability, transcription and metabolism of mock- and A/WSN/33(H1N1)-infected human retinal pigment epithelial (RPE) cells. Results: In silico drug-target interaction analysis revealed that many drugs, such as acetylsalicylic acid, atorvastatin, candesartan, and hydroxocobalam, could target and modulate FLUAV-host cell interaction. In vitro experiments showed that these and other compounds at non-cytotoxic concentrations differently affected transcription and metabolism of mock- and FLUAV-infected cells. Conclusion: Many commonly prescribed drugs modulate FLUAV-host cell interactions in vitro and therefore could affect their interplay in vivo, thus, contributing to morbidity and mortality of patients with influenza virus infections.

It remains poorly understood how the life history strategies and transmission ecologies of viruses of plants, arthropods, and vertebrates are interrelated. The present analysis hinges on the virus transmission success. Virus transmission reflects where in the host-body viruses are retained or replicating. Plants, arthropods, and vertebrates share a protective outer-layer, a circulatory system, and reproductive organs. The latter enables vertical virus transmission and associates with virus-host mutualism. Two broadly opposing virus life history strategies are considered. Acute viruses tend to be replicative and are swiftly transmitted to the next host. Instead, persistent viruses keep virus replicating costs and host damage to a minimum. The intertwined life histories and transmission ecologies are accordingly pieced together, based on the virus mono- or instead dual-host tropism, the location of virus retention or replication on or in the host-body, the presence of cyclical or mechanical transmission by arthropods, and of horizontal and vertical host-to-host transmission modes. It is shown that in the arthropod and in the vertebrate animal host, virus circulation in the hemocoel or blood circulation goes hand-in-hand with vertical transmission. Instead, plant phloem viruses do not transmit via seed. The latter is the rule for the plant-only viruses. The risk management implications are discussed in brief.

The success of many viruses depends upon cooperative interactions between viral genomes. For example, viruses that coinfect the same cell can share essential gene products, such as replicase, the enzyme that replicates the viral genome. However, when cooperation occurs, there is the potential for ‘cheats’ to exploit that cooperation. We suggest that: (1) the biology of viruses makes viral cooperation particularly susceptible to cheating; (2) cheats are common across a wide range of viruses, including viral entities that are already well studied, such as defective interfering genomes, and satellite viruses. Consequently, evolutionary theory developed to explain cheating offers a conceptual framework for understanding and manipulating viral dynamics. At the same time, viruses offer unique opportunities to study how cheats evolve, because cheating is relatively common in viruses, compared with taxa where cooperation is more usually studied, such as animals.

This article develops a multi-perspective view on motivations and methods for tobamovirus purification through the ages, and presents a novel efficient, easy-to-use approach that can be well-adapted to different species of native and functionalized virions. We survey the various driving forces prompting researchers to enrich tobamoviruses: from the search for the causative agents of mosaic diseases in plants to their increasing recognition as versatile nanocarriers in biomedical and engineering applications. Best practice and also rarely applied options for the serial processing steps required for successful isolation of tobamoviruses are then reviewed. Adaptations for distinct particle species, pitfalls and 'forgotten' or underrepresented technologies are considered as well. The article is topped off with our own development of a method for virion preparation, rooted in historical protocols. It combines selective re-solubilization of polyethylene glycol (PEG) virion raw precipitates with density step gradient centrifugation in biocompatible iodixanol formulations, yielding ready-to-use particle suspensions. This newly established protocol and some considerations for perhaps worthwile further developments could serve as putative stepping stones towards preparation procedures appropriate for routine practical uses of the multivalent soft-matter nanorods.

Invasive weeds cause significant crop yield and economic losses in agriculture. The highest in-direct impact may be attributed to the role of invasive weeds as virus reservoirs especially within the commercial growing areas. The new tobamovirus tomato brown rugose fruit virus (ToBRFV), recently identified in the Middle-East, overcomes the Tm-22 resistance allele in the cultivated tomato varieties grown in greenhouses. In this study, we determined the role of invasive weed species as potential hosts for ToBRFV and pepino mosaic virus (PepMV). Out of all tested weed species, the invasive species So-lanum elaeagnifolium and S. rostratum, mechanically inoculated with ToBRFV, were positive for To-BRFV in both enzyme linked immunosorbent assay (ELISA) and RT-PCR tests. S. rostratum was also positive for PepMV. No conspicuous phenotype was observed on ToBRFV infected S. elaeagnifolium plants suggesting a hostplant associated defense response. S. rostratum plants inoculated with either ToBRFV alone or a mixture of ToBRFV and PepMV-IL, contained high ToBRFV levels. In addition, when inoculated with ToBRFV or PepMV-IL disease symptom manifestations were observed in S. rostratum plants and the symptoms were exacerbated upon mixed infections with both viruses. The distribution and abundance of both Solanaceae species increase the risks of virus transmission between species.

Human papillomavirus (HPV) uses the cellular trafficking machinery to reach the cell nucleus and initiate a successful infection. The HPV capsid consists of two proteins: L1 (the major capsid protein) and L2 (minor capsid protein), and L2 is known to be responsible for trafficking the viral genome to the nucleus. From previous studies, we know that many cellular proteins interact with L2 and are involved in the trafficking process at different stages of the infectious entry process. To further investigate how HPV-16 achieves successful viral entry, we have performed a mass spectrometry analysis to identify novel interacting proteins that associate with incoming HPV-16 virions. We show that HPV-16 pseudovirions interact with a group of cellular cargo proteins (COPI), and here we confirm that this is mediated by the direct binding of L2, but not L1, to the COPB1 subunit. We also show that the ability of L2 to interact with COPB1 is conserved in both low- and high-risk HPV types. Furthermore, we also show that the interaction is essential for successful infection entry of multiple HPV types, thereby identifying a novel constituent of the infectious entry pathway of the HPV.

Canine distemper virus (CDV) is a serious contagious disease of canines, cats and sometimes ra-coons. The study included seven raccoons from Timisoara Zoo. The detection of CDV in all raccoons was accomplished using qRT-PCR, but several other exams were also conducted. Clinically, severe digestive disorders were observed, characterized by diarrhea and repeated hematemesis. Pseudomembranous gastroenteritis, congestion and pulmonary edema were found during the ne-cropsy of two racoons. Immunohistochemically, the brown color was highlighted in the examined sectionsand it was present in the cytoplasm of the cells from the germinal centers of the medullary area. Histopathological examination revealed lymphocyte depletion and intranuclear and intracy-toplasmic inclusions in the intestine. Based on the qRT-PCR assay, laboratory tests and lesions ob-served, it was established that the raccoons got infected with CDV, and two of them died as a result. The necropsy, histological lesions and immunohistochemical results are comparable between dogs and racoons. Through the results obtained, it was concluded that the interspecific infection is possible and the epidemiological risk of infection transmitted by racoons to domestic animals, such as dogs and cats, needs to be examined in the future.

BK polyomavirus (BKPyV) causes a lifelong chronic infection and is associated with debilitating disease in kidney transplant recipients. Despite its importance, aspects of the virus life cycle remain poorly understood. In addition to the structural proteins, the late region of the BK genome encodes for an auxiliary protein called agnoprotein. Studies on other polyomavirus agnoproteins have suggested that the protein may contribute to virion infectivity. Here, we demonstrate an essential role for agnoprotein in BK virus release. Viruses lacking agnoprotein do not propagate to wild-type levels and fail to release from host cells. Despite this, loss of agnoprotein does not impair virion infectivity or morphogenesis. Instead, agnoprotein expression correlates with nuclear egress of BK virions. We demonstrate that the agnoprotein binding partner α-SNAP is necessary for BK virion release, and siRNA knockdown of α-SNAP prevents nuclear release of wild-type BK virions. These data highlight a novel role for agnoprotein and begin to reveal the mechanism by which polyomaviruses leave an infected cell.

The recently discovered Jingmenvirus group includes viruses with a segmented genome, RNA of a positive polarity, and several proteins with distant homology to the proteins of the members of the genus Flavivirus. Some Jingmenvirus group members, namely Alongshan virus (ALSV) and Jingmen tick virus, are reported to be tick-borne human pathogens, causing a wide variety of symptoms. ALSV is widely distributed in Eurasia, yet there is no reliable assay for its detection. Here, we describe a qPCR system for the detection of ALSV. Our data show that this system can detect as low as 10⁴ copies of ALSV in the probe. It shows no amplification with common tick-borne viruses circulating in Eurasia, Yanggou tick virus—another member of the Jingmenvirus group—or some known members of the genus Flavivirus. The qPCR system was tested have no non-specific signal for Ixodes ricinus, I. persulcatus, Dermacentor reticulatus, D. marginatus, Haemaphysalis concinna, and H. japonica ticks. Overall, the qPCR system described here can be used for reliable and quantitative ALSV detection.

More than 20 years after the discovery of the first anelloviruses (AVs), they still remain a mysterious group of viruses. To date, there is no clear understanding of their impact on the host organism, although information is emerging about their participation in various pathologies. However, it is well known that AVs are an important component of the human virome. In the current study we assessed the abundance of AVs in viromes from four nasal and pharyngeal samples from children with respiratory symptoms using a metagenomic approach. It is worth noting that three patients had known respiratory viruses and one did not have any. Regarding AVs, they were detected in all samples, namely Torque teno mini virus (TTMV). The greatest abundance and diversity of AVs (Torque teno virus (TTV), TTMV and Torque teno midi virus (TTMDV)) were shown in a diseased patient with an absence of respiratory viruses, which may indicate the potential involvement of AVs in the maintenance of respiratory symptoms. An activated immune system to combat the main pathogens, against the background of which the number of AVs decreases, is discussed as a possible reason for the reduced diversity of anellome in other patients. We also compared the results of the metagenomic approach and qPCR for major respiratory viruses, which were in agreement. In addition, metagenomic sequencing made it possible to obtain additional data on viral genomes in order to establish their taxonomic identification and characterize individual viral profiles in patients from the Siberian part of Russia.

The development of compartmentalized neuron culture systems has been invaluable in the study of neuroinvasive viruses, including the alpha herpesviruses Herpes Simplex Virus 1 (HSV-1) and Pseudorabies Virus (PRV). This chapter provides updated protocols for assembling and culturing rodent embryonic superior cervical ganglion (SCG) and dorsal root ganglion (DRG) neurons in Campenot trichamber cultures. In addition, we provide several illustrative examples of the types of experiments that are enabled by Campenot cultures: 1. Using fluorescence microscopy to investigate axonal outgrowth/extension through the chambers, and alpha herpesvirus infection, intracellular trafficking, and cell-cell spread via axons. 2. Using correlative fluorescence microscopy and cryo electron tomography to investigate the ultrastructure of virus particles trafficking in axons.

Cowpea chlorotic mottle virus (CCMV) is a plant virus explored as a nanotechnological platform. The robust self-assembly mechanism of its capsid protein allows for drug encapsulation and targeted delivery. Additionally, the capsid nanoparticle can be used as a programmable platform to display different molecular moieties. In view of future applications, efficient production and purification of plant viruses is a key step. In established protocols, the need for ultracentrifugation is a significant limitation due to cost, difficult scalability, and safety issues. In addition, the purity of the final virus isolate often remains unclear. Here, an advanced protocol for the purification of CCMV from infected plant tissue was developed, focusing on efficiency, economy, and final purity. The protocol involves precipitation with PEG 8000, followed by an affinity extraction using a novel peptide aptamer. The efficiency of the protocol was validated using size exclusion chromatography, MALDI-TOF mass spectrometry, reversed-phase HPLC, and sandwich immunoassay. It was demonstrated that the final eluate of the affinity column is of exceptional purity (98.4%) determined by HPLC and detection at 220 nm. The scale-up of our proposed method seems to be straightforward, which opens the way to the large-scale production of such nanomaterials. This highly improved protocol may facilitate the use and implementation of plant viruses as nanotechnological platforms for in vitro and in vivo applications.

SARS-CoV-2, influenza A/B virus (IAV/IBV) and respiratory syncytial virus (RSV) are among the common viruses causing acute respiratory infections. Clinical diagnosis to differentiate these viruses is challenging due to similar clinical presentations, thus laboratory-based real-time RT PCR is the gold standard for diagnosis. The study aimed to evaluate the diagnostic performance of STANDARD M10 Flu/RSV/SARS-CoV-2 (SD Biosensor Inc, Seoul, Korea). This retrospective study was conducted with archived respiratory samples positive and negative for SARS-CoV-2, IAV, IBV or RSV. The evaluation study involved a total of 322 respiratory samples comprising 215 positive samples (49 SARS-CoV-2, 48 IAV, 53 IBV, 65 RSV) and 107 negative samples. All samples were tested with both STANDARD M10 and either Xpert Xpress SARS-CoV-2 or Xpert Xpress Flu/RSV (Cepheid, USA). The sensitivity, specificity, positive predictive value and negative predictive value rates of STANDARD M10 were very similar to Xpert Xpress SARS-CoV-2 or Xpert Xpress Flu/RSV ranges for each virus (98-100%). The overall agreement was 99.4% with 99.1% agreement for positive samples and 100% agreement for negative samples. In conclusion, the STANDARD M10 point-of-care test is suitable for rapid simultaneous detection of SARS-CoV-2, IAV, IBV and RSV.

Hepatitis B virus (HBV) remains a dominant cause of hepatocellular carcinoma (HCC). Recently it was shown that HBV and woodchuck hepatitis virus (WHV) integrate into hepatocyte genome minutes after invasion. Retrotransposons and transposable sequences were frequent sites of the initial insertions suggesting a mechanism for spontaneous HBV DNA disperse throughout hepatocyte genome. Several somatic genes were also identified as early insertional targets in infected hepatocytes and woodchuck livers. Head-to-tail joints (HTJs) dominated amongst fusions indicating their creation by non-homologous-end-joining (NHEJ). Their formation coincided with robust oxidative damage of hepatocyte DNA. This was associated with activation of the poly(ADP-ribose) polymerase 1 (PARP1)-mediated dsDNA repair as reflected by augmented transcription of PARP1 and XRCC1, the PARP1 binding partner, OGG1, a responder to oxidative DNA damage, and by increased activity of NAD+, a marker of PARP1 activation, and HO1, an indicator of cell oxidative stress. The engagement of the PARP1-mediated NHEJ repair pathway explains HTJ format of the initial merges. The findings showed that HBV and WHV are immediate inducers of oxidative DNA damage, hijack dsDNA repair to integrate into hepatocyte genome and by this may initiate pro-oncogenic process. Tracking initial integrations may uncover early markers of HCC and help to explain HBV-associated oncogenesis.

Jingmen viruses are newly described segmented flavi-like viruses that have a worldwide distribution in ticks and have been associated with febrile illnesses in humans. Computational analyses were used to predict that Jingmen flavi-like virus glycoproteins have structural features of class II viral fusion proteins, including an ectodomain consisting of beta-sheets and short alpha-helices, a fusion peptide with interfacial hydrophobicity and a three domain architecture. Jingmen flavi-like virus glycoproteins have a sequence enriched in serine, threonine and proline at the amino terminus, which is a feature of mucin-like domains. Several of the serines and threonines are predicted be modified by the addition of O-linked glycans. Some of the glycoproteins are predicted to have an additional mucin-like domain located prior to the transmembrane anchor, whereas others are predicted to have a stem consisting of two alpha-helices. The flavivirus envelope protein and Jingmen flavi-virus glycoproteins may have diverged from a common class II precursor glycoprotein with a mucin-like domain or domains acquired after divergence.

Background and Aim: Spontaneous bacterial peritonitis is a common infection in liver cirrhosis. This systematic review and meta-analysis provides detailed information on the prevalence of SBP among HBV and HCV-related liver cirrhosis globally. Methods: A systematic search for articles describing the prevalence of SBP in HBV, and HCV related cirrhosis was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines. Our search returned ten (10) eligible articles involving 1,713 viral cirrhosis cases representing eight (8) countries. A meta-analysis was performed on our eligible studies using the random effect model. A protocol was registered with PROSPERO (CRD42022321790). Results: The pooled prevalence of SBP in HBV associated cirrhosis had the highest estimate [8.0% (95% CI, 2.7 – 21.0%; I2= 96.13%; p < 0.001)], followed by SBP in HCV associated liver cirrhosis [4.0% (95% CI, 1.3% – 11.5%; I2 = 88.99%; p < 0.001)]. China (61.8%, CI: 57.1 – 66.3%), the USA (50.0%, CI: 34.6 – 65.4%), and Holland (31.1%, CI: 21.6 – 42.5%) had the highest estimate for SBP in HBV associated liver cirrhosis, SBP in HCV associated liver cirrhosis and SBP in HBV+HCV associated liver cirrhosis respectively. There was a significant difference in the prevalence of SBP in viral hepatitis-associated liver cirrhosis with the year of sampling and method of SBP detection at P<0.001. There was an increase in SBP incidence at the beginning of 2016 across the liver cirrhosis in this study. Conclusion: The findings of this review revealed an increase in the incidence of SBP in viral hepatitis over the last decade, the latter could be due to the global increase in Bacterial resistance. This indicates a possible future rise in the global prevalence of SBP among HBV, and HCV-related liver cirrhosis.

The irregular timing and spatial variation in zoonotic arbovirus spillover from vertebrate hosts to humans and livestock present challenges to predicting their occurrence from year to year and within their broader geographic range, compromising effective prevention and control strategies. The objective of this study was to quantify effects of landscape composition and configuration and dynamic temperature and precipitation values on the 2018 spatiotemporal distribution of eastern equine encephalitis virus (EEEV) (Togaviridae, Alphavirus) and West Nile virus (WNV) (Flaviviridae, Flavivirus) sentinel chicken seroconversion in northeastern Florida using Earth Observation (EO) data and a modeling framework that incorporated joint spatial and temporal effects. We investigated environmental effects using Bernoulli generalized linear mixed effects models (GLMMs) including a site level random effect, and then added spatial random effects and spatiotemporal random effects in subsequent runs. Models were executed using integrated nested Laplace approximation (INLA) and a stochastic partial differential equation (SPDE) approach in R-INLA. GLMMs that included a spatiotemporal random effect performed better relative to models that included only spatial random effects and better than non-spatial models. Results indicated strong spatiotemporal structure in seroconversion for both viruses, but EEEV exhibited more punctuated and compact structure at the beginning of the sampling season, while WNV exhibited more gradual and diffuse structure across the study area toward the end of the sampling season. Percentage of cypress/tupelo wetland land cover within 3500 m of coop sites and edge density of forest land cover within 500 m had a strong positive effect on EEEV seroconversion, while the best fitting model for WNV was the intercept only model with spatiotemporal random effects. Lagged temperature and precipitation variables included in our study did not have a strong effect on seroconversion for either virus when accounting for temporal autocorrelation, demonstrating the utility of capturing this structure to avoid Type I errors. Predictive accuracy on out-of-sample data for EEEV seroconversion demonstrates the potential to develop a temporally dynamic framework to predict arbovirus transmission.

The interaction of human immunodeficiency virus with human cells is responsible for all stages of the viral life cycle, from the infection of CD4+ cells to reverse transcription, integration, and the assembly of new viral particles. To date, a large amount of OMICs data as well as information from functional genomics screenings regarding the HIV-1-host interaction has been accumulated in the literature and in public databases. We processed databases containing HIV-host interactions and found 2910 HIV-1-human protein-protein interactions, mostly related to viral group M subtype B, 137 interactions between human and HIV-1 coding and non-coding RNAs, essential for viral lifecycle and cell defense mechanisms, 232 transcriptomics, 27 proteomics, and 34 epigenomics HIV-related experiments. Numerous studies regarding network-based analysis of corresponding OMICs data have been published in recent years. We overview various types of molecular networks, which can be created using OMICs data, including HIV-human protein-protein interaction networks, co-expression networks, gene regulatory and signaling networks, and approaches for the analysis of their topology and dynamics. The network-based analysis can be used to determine the critical pathways and key proteins involved in the HIV life cycle, cellular and immune responses to infection, viral escape from host defense mechanisms, and mechanisms mediating different susceptibility of humans to infection. The proteins and pathways identified in these studies may represent a basis for developing new anti-HIV therapeutic strategies such as new small-molecule drugs preventing infection of CD4+ cells and viral replication, effective vaccines, "shock and kill" and "block and lock" approaches to cure latent infection.

Canine infectious respiratory disease complex (CIRDC) is caused by different viruses and bacteria. Viruses associated with CIRDC include canine adenovirus-2 (CAV-2), canine distemper virus (CDV), canine influenza virus (CIV), canine herpesvirus (CHV), canine coronavirus (CCoV) and canine parainfluenza virus (CPIV). Bacteria associated with CIRDC include Bordetella bronchiseptica, Streptococcus equi subspecies zooepidemicus, and Mycoplasma spp. The present study examined the prevalence of pathogens associated with CIRDC in specimens received by a Veterinary Diagnostic Laboratory in Georgia from 2018 to 2022. Out of 459 cases, viral agents were detected in 34% cases and bacterial agents were detected in 58% cases. A single pathogen was detected in 31% cases, while two or more pathogens were identified in 24% cases. The percentages of viral agents identified were CAV-2 (4%), CDV (3%), CPIV (16%), CCoV (7%), and CIV (2%). The percentages of bacterial agents were Bordetella bronchiseptica (10%), Mycoplasma canis (24%), Mycoplasma cynos (21%), and S treptococcus zooepidemicus (2%). Positive viral cases ranged from 2-4% for CAV-2, 1-7% for CDV, 1-4% for CHV, 9-22% for CPIV, 4-13% for CCoV, and 1-4% for CIV. Overall, the study showed that the most prevalent pathogens associated with CIRDC during the study period were CPIV, M. canis, and M. cynos.

The World Health Organization has estimated an annual occurrence of approximately 392 million Dengue virus (DENV) infections in more than 100 countries where the virus is endemic, and this represents a serious threat to humanity. DENV is a serologic group with four distinct serotypes (DENV-1, DENV-2, DENV-3, and DENV-4) belonging to the genus Flavivirus, in the family Flaviviridae. Dengue is the most widespread mosquito-borne disease in the world. The ~10.7 kb DENV genome encodes three structural proteins (capsid [C], pre-membrane [prM], and envelope [E]) and seven non-structural (NS) proteins (NS1, NS2A, NS2B, NS3, NS4A, NS4B, and NS5). The NS1 protein is a membrane-associated dimer and a secreted, lipid-associated hexamer. Dimeric NS1 is found on membranes both in cellular compartments and cell surfaces. Secreted NS1 (sNS1) is often present in patient serum at very high levels, which correlates with severe dengue symptoms. This study was conducted to discover how NS1 protein, microRNAs-15/16 (miRNAs-15/16), and apoptosis are related during DENV-4 infection in human liver cell lines. Huh 7.5 and HepG2 cells were infected with DENV-4, and miRNAs-15/16, viral load, NS1 protein, and caspases-3/7 were quantified after different times of infection. This study demonstrated that miRNAs-15/16 are overexpressed during infection of HepG2 and Huh 7.5 cells by DENV-4 and have a relationship with NS1 protein expression, viral load, and activity of caspases-3/7, thus making these miRNAs potential injury markers during DENV infection in human hepatocytes.

The Human Herpesviruses persist in the form of a latent infection in specialized cell types. During latency, the herpesvirus genomes associate with cellular histone proteins and the viral lytic genes assemble into transcriptionally repressive heterochromatin. Although there is divergence in the nature of heterochromatin on latent herpesvirus genomes, in general the genomes assemble into forms of heterochromatin that can convert to euchromatin to permit gene expression and therefore reactivation. This reversible form of heterochromatin is known as facultative heterochromatin and is most commonly characterized by polycomb silencing. Polycomb silencing is prevalent on the cellular genome and plays a role in developmentally regulated and imprinted genes, as well as X chromosome inactivation. As herpesviruses initially enter the cell in an un-chromatinized state, they provide an optimal system to study how de novo facultative heterochromatin is targeted to regions of DNA and how it contributes to silencing. Here, we describe how polycomb-mediated silencing potentially assembles onto herpesvirus genomes, synergizing what is known about herpesvirus latency with facultative heterochromatin targeting to the cellular genome. A greater understanding of polycomb silencing of herpesviruses will inform on the mechanism of persistence and reactivation of these pathogenic human viruses and provide clues regarding how de novo facultative heterochromatin forms on the cellular genome.

Novel Coronavirus infection mediated pandemic started in China in December 2019 and is still killing 1000s of people throughout the world. The second most populous country, India too is fighting against this infectious disease. The country is taking effective measures to curb the pandemic by exerting extensive campaigning on sanitation and strict social distancing measures to quell the explosion of the infection rate. The future of the COVID-19 infections in India still remain unpredictable, so precautionary methods need to be continued until the growth rate of new cases drop below one.

The Tumor Microenviroment (TME) is a complex milieu that is increasingly recognized as a key factor in multiple stages of disease progression and responses to therapy as well as escape from immune surveillance. However, the precise contribution of specific immune effector and immune suppressor components of the TME in Burkitt lymphoma (BL) remains poorly understood. In this paper, we applied the computational algorithm CIBERSORT to Gene Expression Profile (GEP) datasets of 40 BL samples to draw a map of immune and stromal components of TME. Furthermore, by VECTRA multispectral immunofluorescence (IF) and multiple immunohistochemistry (IHC), we investigated the TME of an additional series of 40 BL cases and evaluated the possible role of the PD-1/PD-L1 immune checkpoint axis. Our results indicated that M2 polarized macrophages are the most prominent TME component in BL. In addition, we investigated the correlation between PD-L1 and latent membrane protein-2A (LMP2A) expression on tumour cells, highlighting a subgroup of BL cases characterized by a non- canonical latency program of EBV with an activated PD-L1 pathway. In conclusion, our study analysed the TME in BL and identified a tolerogenic immune signature highlighting new potential therapeutic targets.

For many years marine algae has been subject of numerous researches and as a source of natural products with antiviral activity, such as terpenes, alkaloids and sulphated polysaccharides. However, the anti-Zika virus (ZIKV) potential of algae has not been studied. In this study we evaluated extracts seven species of the three major classes of seaweeds (Phaeophyceae, Chlorophyceae and Rhodophyceae) against ZIKV. All seaweeds tested are native of the Brazilian coast, except for Kappaphycus alvarezii that can be cultivated. ZIKV a mosquito-borne flavivirus, has become a public health problem. In recent years there has been an increase in the number of cases and a strong association between ZIKV outbreak and the spread of cases of Guillain-Barré Syndrome and microcephaly. All seaweed extracts tested in this work inhibits ZIKV replication in a dose-dependent manner. Caulerpa racemosa, Kappaphycus alvarezii and Osmundaria obtusiloba extracts were able to inhibit viral replication at low concentrations with EC₅₀ values ranging from 1.38 to 1.98 µg/mL. We observed that O. obtusiloba presented a significant virucidal effect. Our results suggest that extracts of C. racemosa, K. alvarezii and O. obtusiloba presented very promising results, being excellent candidates for further studies, demonstrating that marine algae are an interesting source for the development of novel anti-ZIKV agents.

Respiratory syncytial virus (RSV) infection is a major cause of severe respiratory disease in infants and young children worldwide. Two vaccines targeting the elderly and pregnant women have been recently approved employing the prefusion form of the RSV-fusion protein (F). However, there are currently no vaccines for infants. Studies have shown a fusion-inactive prefusogenic F form is significantly more immunogenic and produces higher antibody titers to both the prefusion and postfusion structures of the F protein. Here we have developed RSV virus-like particles (RSV-VLPs) consisting of prefusogenic F, RSV glycoprotein and matrix proteins, produced them using the baculovirus expression system, and studied their protective efficacy in Balb/c mice. Morphology and successful assembly of VLPs were confirmed by transmission electron microscopy and western blot. Mice immunized with VLPs developed high levels of serum IgG and neutralizing antibodies as compared with mice immunized with inactivated virus. The VLP vaccine also induced higher levels of IFNγ and IL4, elicited limited proliferation of CD4+ and CD8+ T cells but higher cytotoxic-T-lymphocyte responses. VLP immunization abolished lung pathology in the mice after RSV challenge. Overall, our results indicate that RSV-VLPs consisting of prefusogenic F, glycoprotein and matrix proteins are a potential vaccine candidate against RSV.

The Influenza A virus (IAV) is a highly infectious virus that poses a significant threat to global public health and food supplies. The current subtype of avian influenza virus (AIV), H5N1, is being closely monitored worldwide due to its unprecedented spread from Europe to North America and now to Central and South America. This review summarizes recent updates on the evolution of the different IAV subtypes in birds and mammals including humans, in Chile. The distribution and spread of AIV H5N1 in Chile indicated a complex interplay between ecological and human factors in that it was negatively correlated with distance to the closest urban center and precipitation and temperature seasonality. It is evident that highly pathogenic avian influenza (HPAI) H5N1 in Chile was introduced from North America via the Atlantic migratory flyways as opposed to local transmission from other countries in South America. The presence of these viruses in Chile underscores the need for increased biosecurity on poultry farms and continuous genomic surveillance approaches to understand and control AIVs in both wild and domestic bird populations in Chile.

Chronic hepatitis B (CHB) infection and the Hepatitis B virus X protein (HBx) are major risk factors associated with hepatocellular carcinoma (HCC). In CHB infection, HBx induces mitochondrial dysfunction, exhaustion and impaired function in hepatocytes. Restoring hepatocyte health along with reduction in virus replication could be an ideal treatment for CHB. Thiourea derivatives are well known for their antiviral property though their effect on mitochondrial and/ or hepatocyte health remains obscure. This study focus on the repurposing of thiourea derivatives (DSA-00, DSA-02, and DSA-09) on hepatocyte replenishment. HepG2.2.15 cells were treated with thiourea derivatives, alongside Entecavir (ETV). The proteomics analysis showed both DSA-00 and ETV were enriched with proteins associated with antiviral responses. In addition, DSA-00 additionally showed increase in proteins linked to mitochondrial response. Whereas DSA-02 exhibited association with innate immune system and citric acid cycle and DSA-09 displayed pathways similar to DSA-00 and ETV. Treated groups exhibited enhanced bio-energetic and antiviral response as compared to the untreated group. FACS analysis revealed the restoration of exhausted hepatocytes by thiourea derivatives through targeting mitochondria. Our findings suggest that thiourea derivatives hold potential as a novel therapeutic agent that seems to restore mitochondrial health along with anti-viral response in CHB.

To gain new insights into the potential of mother-to-child transmission of Zika virus (ZIKV) through breast milk or breastfeeding practices, we systematically searched regional and international databases and screened 1,658 non-duplicate records describing women with suspected or confirmed ZIKV infection, intending to breastfeed or give breast milk to an infant. Fourteen studies met our inclusion criteria and inform this analysis. These studies reported on 97 mother-children pairs who provided breast milk for ZIKV assessment. Seventeen breast milk samples from different women were found positive for ZIKV via RT-PCR, and ZIKV replication was found in cell cultures from five out of seven breast milk samples from different women. Only three out of six infants who had ZIKV infection were breastfed, no evidence of clinical complications were found to be associated with ZIKV RNA in breast milk. This review updates our previous report by synthesizing the evidence from 12 new articles and we find no evidence of mother-to-child transmission through breast milk intake or breastfeeding. As the certainty of the present evidence is low, additional studies are still warranted to completely understand any potential of transmission of ZIKV through breastfeeding.

Zika virus (ZIKV) is a flavivirus that originated in Africa but emerged in Latin America in 2015. In this region, other flaviviruses such as Dengue (DENV), West Nile, and Yellow Fever Virus (YFV) also circulate, allowing for possible antigenic cross-reactivity to impact viral infections and immune responses. Studies have found antibody mediated enhancement between DENV and ZIKV, but the impact of YFV antibodies on ZIKV infection has not been fully explored. ZIKV infections cause congenital syndromes, such as microcephaly, necessitating further research into ZIKV vertical transmission through the placental barrier. Recent advancements in biomedical engineering have generated co-culture methods that allow for in vitro recapitulation of the maternal: fetal interface. This study utilized a transwell assay, which is a co-culture model utilizing human placental syncytiotrophoblasts, fetal umbilical cells, and a differentiating embryoid body to replicate the maternal: fetal axis. To determine if cross reactive YFV vaccine antibodies impact the pathogenesis of ZIKV across the maternal fetal axis, maternal syncytiotrophoblasts were inoculated with ZIKV or ZIKV incubated with YFV vaccine anti-sera, and viral load was measured 72 hours post inoculation. Here we report that BeWo and HUVEC cells are permissive to ZIKV and that the impact of YFV post-vaccination antibodies on ZIKV replication is cell line dependent. Embryoid bodies are also permissive to ZIKV and the presence of YFV antibodies collected 1 to 6 months post vaccination enhances ZIKV infection. Our data show that each of the cell lines and EBs have a unique response to ZIKV complexed with post-vaccination serum suggesting there may be cell-specific mechanisms that impact congenital ZIKV infections. Since ZIKV infections can cause severe congenital syndromes, it is crucial to understand any potential enhancement or protection offered from cross-reactive, post-vaccination antibodies.

With ongoing colony losses driven in part by the Varroa mite and the associated exacerbation of virus load, there is an urgent need to protect honey bees (Apis mellifera) from fatal levels of virus infection and from nontarget effects of insecticides used in agricultural settings. A continuously replicating cell line derived from the honey bee would provide a valuable tool for study of molecular mechanisms of virus – host interaction, for screening of antiviral agents for potential use within the hive, and for assessment of the risk of current and candidate insecticides to the honey bee. However, the establishment of a continuously replicating, honey bee cell line has proved challenging. Here we provide an overview of attempts to establish primary and continuously replicating hymenopteran cell lines, methods (including recent results) for establishing honey bee cell lines, challenges associated with the presence of latent viruses (especially Deformed wing virus), in established cell lines and methods to establish virus-free cell lines. We also describe the potential use of honey bee cell lines in conjunction with infectious clones of honey bee viruses for examination of fundamental virology.

The recent outbreak of the new virus in Wuhan city, China from the sea food market has led to the identification of a new strain called the corona virus and named as novel corona virus (2019-nCoV) belonging to Coronaviridae family. This has created major havoc and concern due to the mortality of 250 persons and affecting more than 10,000 people. This virus causes sudden fever, pneumonia and also kidney failure. In this study a computational approach is proposed for drug and vaccine design. The spike protein sequences were collected from a protein database and analysed with various bioinformatics tools to identify suitable natural inhibitors for the N-terminal receptor binding domain of spike protein. Also, it is attempted to identify suitable vaccine candidates by identifying B-Cell and T-cell epitopes. In the drug design, the tanshinone Iia and methyl Tanshinonate were identified as natural inhibitors based on the docking score. In the vaccine design, B-cell epitope VLLPLVSSQCVNLTTRTQLPPAYTN was found to have the highest antigenicity. FVFLVLLPL of MHC class-I allele and FVFLVLLPL of MHC class-II allele were identified as best peptides based on a number of alleles and antigencity scores. The present study identifies natural inhibitors and putative antigenic epitopes which may be useful as effective drug and vaccine candidates for the eradication of novel corona virus.

Aedes aegypti (L.) is the primary vector of chikungunya, dengue, yellow fever and Zika viruses. The leucine-rich repeats (LRR)-containing domain is evolutionarily conserved in many proteins associated with innate immunity in invertebrates and vertebrates, as well as plants. We focused on the AaeLRIM1 and AaeAPL1 gene expressions in response to Zika virus (ZIKV) and Chikungunya virus (CHIKV) infection using a time course study, as well as the developmental expressions in the eggs, larvae, pupae, and adults. RNA-seq analysis data provided 60 leucine-rich repeat related transcriptions in Ae. aegypti in response to Zika virus (Accession number: GSE118858, https://www.ncbi.nlm.nih.gov/gds/?term=GSE118858). RNA-seq analysis data showed that AaeLRIM1 (AAEL012086-RA) and AaeAPL1 (AAEL009520-RA) were significantly upregulated 2.5 and 3-fold during infection by ZIKV 7-days post infection (dpi) of an Ae. aegypti Key West strain compared to an Orlando strain. The qPCR data showed that LRR-containing proteins AaeLRIM1, AaeAPL1 and five paralogues were expressed 100-fold lower than other nuclear genes, such as defensin, during all developmental stages examined. Together, these data provide insights into transcription profiles of LRR proteins of Ae. aegypti during its development and in response to infection with emergent arboviruses.

In 2015 in Brazil, Zika virus showed features of geographic expansion and potentially increased virulence. In 2016, New York State issued emergency regulations after the World Health Organization declared Zika virus a Public Health Emergency of International Concern. In this study, mosquito surveillance was conducted in Westchester County, New York, to identify Zika virus and other arboviruses. Twenty trap sites were used for surveillance of Aedes albopictus mosquitoes, the Zika virus vector. The Westchester County Department of Health performed testing for Zika, West Nile, Eastern equine encephalitis, and other flaviviruses on 369 batches comprising 8,891 mosquitoes. Aedes albopictus mosquitoes were identified in Nassau, Rockland, Suffolk, Westchester, and New York City. Despite the increased capacity for specimen analysis, Zika virus was not detected. This study provides the first evidence of appropriate Zika virus surveillance. However, the results do not allow determination of the potential mechanism of local vector-to-human transmission of Zika virus among Aedes albopictus mosquitoes. This study adds to the evidence regarding the distribution, emergence, and trapping capabilities of potential Zika virus vectors.

Background: Humoral memory and specific antibodies levels depend on kind of the antigen and individual immunofactors., The presence of IgM antibodies or fourfold rise in specific IgG level, are generally accepted as diagnostic in serology of acute viral infection. This basic model is not adequate for herpesvirome especially after hematopoietic stem cell transplantation (HSCT) due to continuous, usually multifocal antigenic stimulation, various donor serostatus, immunosuppresion and individual immunoreconstitution. Methods: A  case-control study was conducted for identifying cases of Human herpesviruses (HHV) active infection (from 300 diagnosed immunocompromised patients) and evaluating historically associated humoral factors to look at outcomes. We enrolled only patients’ data with meticulous differential diagnosis to exclude other causes, thereby observe pathways and temporal relationships, not statistical ones, usually collected in cohorts. Despite the small number such data collection and analysis avoids a number of biases and indicates cause and effect.Results. In the observational study retrospective analysis of data from 300 patients with clinical diagnosis of herpes simplex (HSV) and varicella zoster virus(VZV) reactivation showed a number of biases. In two well differentiated cases (confirmed by Tzanck test) with various disease and conditioning evolution of immunoparameters showed interesting pathway. Exponential decrease of specific IgG after HSCT precedes virus replication with cytopathic effect (shingles, VZV-encephalitis and HSV-induced mucositis). Minima (smallest IgG levels) before herpes virus reactivation were 234,23 mIU/ml and 94 RU/ml for VZV and HSV, respectively. This coincides with low CD4 titer, but without other infectious process. Other immune response parameters such as Treg, cytotoxic T cells, complement and total IgG level were quite the same as before the transplant procedure. Interestingly, the second wave of immunoreconstitution with anamnestic antibody response was not always observed. It coincided with prolonged herpes viral infection. Patient with lymphocyte depletion in conditioning showed earlier second wave of immunoreconstitution (6th vs 14th month) Conclusions: Typical for infancy kinetics of IgG level is unique after HSCT (the decline phase is first). Host-microbiome factors (i.e. HHV1-3 -serostatus) should be taken into account to predict risk of non-relapse mortality and survival after HSCT. The levels of specific antibodies help to predict the prognosis and improve the management. The lack of differentiation, assessor and confusing bias are the main obstacles in statistical HHV1-3 research. Such time-lapse case studies may be first to build evidence of a pathway and association between immunoparameters and HHV disease.

The pathogenesis of porcine circovirus type 2b (PCV2b) and swine influenza A virus (SwIV) during co-infection in swine respiratory cells is poorly understood. To elucidate the impact of PCV2b/SwIV co-infection, newborn porcine tracheal epithelial cells (NPTr) and immortalized porcine alveolar macrophages (iPAM 3D4/21) were co-infected with PCV2b and SwIV (H1N1 or H3N2 genotype). Viral replication, cell viability and cytokine mRNA expression were determined and compared between single-infected and co-infected cells. Finally, 3’mRNA sequencing was performed to identify the modulation of gene expression and cellular pathways in co-infected cells. It was found that PCV2b significantly decreased and improved SwIV replication, in co-infected NPTr and iPAM 3D4/21 cells respectively, compared to single infected cells. Interestingly, PCV2b/SwIV co-infection synergistically up-regulated IFN expression in NPTr cells whereas in iPAM 3D4/21 cells, PCV2b impaired the SwIV IFN induced response, both correlating with SwIV replication modulation. RNA-sequencing analyses revealed that the modulation of gene expression and enriched cellular pathways during PCV2b/SwIV H1N1 co-infection is regulated in a cell type-dependent-manner. This study revealed different outcomes of PCV2b/SwIV co-infection in porcine epithelial cells and macrophages and provides new insights on porcine viral co-infections pathogenesis.

Rapid spread of African swine fever virus (ASFV), causing severe disease with often high fatality rates in Eurasian suids, prevails as a threat for pig populations and dependent industries world-wide. Although advancing scientific progress continually enhances our understanding of ASFV pathogenesis, alternative transmission routes for ASFV have yet to be assessed. Here, we demonstrate that ASFV can efficiently be transferred from infected boars to naïve recipient gilts through artificial insemination (AI). In modern pig production, semen from boar studs often supplies many sow herds. Thus, the infection of a boar stud presents the risk of rapidly and widely distributing ASFV within or between countries. Daily blood and semen collection from four boars after intramuscular inoculation with ASFV strain ‘Estonia 2014’ resulted in detection of ASFV genomes in the semen as early as 2 dpi, in blood at 1 dpi while semen quality remained largely unaffected. Ultimately, after insemination with extended semen, 7 of 14 gilts were ASFV positive by 7 days post insemination, and all gilts were ASFV positive by 35 days post insemi-nation. Twelve out of 13 gilts aborted at the onset of fever. A proportion of fetuses originating from the remaining gilt showed both abnormalities and replication of ASFV in fetal tissues. Thus, we present evidence for the efficient transmission of ASFV to gilts via AI and also to im-planted embryos. These results underline the critical role that boar semen could play in ASFV transmission.

Quebec is the third-largest wine grape producing province in Canada, and the industry is constantly expanding. Traditionally, 90% of the grapevine cultivars grown in Quebec were rustic or semi-rustic and largely dominated by winter hardy interspecific hybrid Vitis sp. cultivars. Over the years, the winter protection techniques adopted by growers and climate changes have offered an opportunity to establish V. vinifera L. cultivars (e.g. Pinot Noir). We characterized the virome of leafroll-infected interspecific hybrid cultivar and compared it to the virome of V. vinifera cultivar to support and facilitate the transition of the industry. A dsRNA sequencing method was used to sequence symptomatic and asymptomatic grapevine leaves of different cultivars. The results suggested a complex virome in terms of composition, abundance, richness, and phylogenetic diversity. Three viruses, grapevine Rupestris stem pitting-associated virus, grapevine leafroll-associated virus (GLR) 3 and 2 and hop stunt viroid (HSVd) largely dominated the virome. However, their presence and abundance varied among grapevine cultivars. The symptomless grapevine cultivar Vidal was frequently infected by multiple virus and viroid species and different strains of the same virus, including GLR virus 3 and 2. Our data shows that viruses and viroids associated with the highest number of grapevines expressing symptoms included HSVd, GLR3 and GLR2, in gradient order. However, co-occurrence analysis revealed that the presence of GLR species was randomly associated with the development of virus-like symptoms. These findings and their implication for grapevine leafroll disease management were discussed.

The work is devoted to the investigation of virus quasispecies evolution and diversification due to mutations, competition for host cells, and cross-reactive immune responses. The model consists of a nonlocal reaction-diffusion equation for the virus density depending on the genotype considered as a continuous variable and on time. This equation contains two integral terms corresponding to the nonlocal effects of virus interaction with host cells and with immune cells. In the model, a virus strain is represented by a localized solution concentrated around some given genotype. Emergence of new strains corresponds to a periodic wave propagating in the space of genotypes. The conditions of appearance of such waves and their dynamics are described.

Background: Respiratory syncytial virus[ RSV] is a lethal overwhelming defectiveness that influences people all over the world. The infection gets down in the lower respiratory tract and does not disperse to the remainder of the body. The objective of the study: Bioinformatics was used to create an mRNA vaccine against the Respiratory syncytial virus( RSV). Methodology: Lipid nanoparticle vaccines containing the Respiratory syncytial virus's surface fusion protein's mRNA were created for the current screening experimental investigation. Lipid nanoparticles[ LNP] with a particle size of around 90 nanometres that were created using the hot micro-emulsion process comprise the current vaccine delivery system. In stages 1 and 2 of clinical trials, the immunogenicity of the current mRNA RSV vaccine was evaluated. Results: The current vaccine demonstrated 81% immunogenicity in animal testing, but only 69% in stages 1 and 2 of clinical trials. Its side effects were manageable. The results persisted for a while. In the current trial, the vaccination proved effective as a preventative measure against RSV infection. The current immunization lacks antibody-dependent enhancement, which causes non-protective antibodies to develop. These non-neutralizing antibodies worsen infection by enhancing viral entrance and replication in the host cells, activating cytokines and the complement cascade through the production of immunological complexes, or both. However, the current LPN-RSV mRNA vaccine of the surface fusion protein resulted in the formation of potent neutralizing antibodies with persistent protection, especially for newborns and elderly individuals who get the ideal dose regimen. Conclusion: The invention of the LNP-mRNA RSV vaccine, which might prevent RSV-caused bronchiolitis and fatal pneumonia, made the current study promising