Abstract: Background: From 2018-2021, travel-related extensively drug-resistant (XDR) Salmonella Typhi was identified in Ontario, Canada. There remain opportunities to characterize typhoidal Salmonella antimicrobial susceptibility trends within a large health authority in British Columbia, Canada. Methods: This retrospective study included patients with Salmonella Typhi or Paratyphi A, B or C bacteremia identified at Fraser Health regional microbiology laboratory from 2018-2024. Primary outcome was proportion of cases with multi-drug resistant (MDR) and XDR typhoidal Salmonella. Secondary outcomes included annual antimicrobial susceptibility for ampicillin, ceftriaxone, ciprofloxacin, trimethoprim-sulfamethoxazole, ertapenem, meropenem and azithromycin. Clinical outcomes included hospitalization length, and 30-day mortality, clinical cure and infection relapse. Results: Among 271 patients, most were previously healthy and recently travelled. There were extended spectrum beta-lactamase (1.1%) and MDR (1.5%) typhoidal Salmonella, with no XDR cases observed. In 2024, ciprofloxacin resistance was 96% while susceptibility rates were high for other studied antimicrobials. Within 30 days, no deaths were reported; however, 6 patients (3%) had infection relapse. Conclusion: Currently in British Columbia, MDR typhoidal Salmonella remains rare. Empiric ciprofloxacin should be avoided due to persistently high resistance rates. With ongoing travel patterns, it is beneficial for institutions to continue typhoidal Salmonella antimicrobial susceptibility surveillance, and travelers should seek pre-travel health assessments.

Abstract:

Neurobrucellosis is a rare but serious complication of brucellosis, a zoonotic disease caused by bacteria of the genus Brucella. The most common clinical manifestations of neurobrucellosis include meningitis, encephalitis, and seizures. The diagnosis of neurobrucellosis should be considered when patients present with undulant fever, lethargy, seizures, or other features of meningitis/encephalitis. Occupational exposure to Brucella bacteria, particularly through contact with infected animals or their products, is a significant risk factor for developing neurobrucellosis. Certain occupations, such as farmers, veterinarians, and slaughterhouse workers, are at a higher risk of exposure. Recent research has suggested a potential link between neurobrucellosis and Parkinson's disease, although further investigation is needed to fully understand this association. Prevention and control of neurobrucellosis involve measures such as occupational hygiene, vaccination of livestock, and public education campaigns.

Abstract: Introduction: Leishmaniasis is a globally widespread zoonotic infection, including in the Mediterranean basin. There are four known types of disease: cutaneous, mucocutaneous, visceral and post Kala-Azar dermal leishmaniasis. Visceral Leishmaniasis (VL) is caused by Leishmania (L.) infantum and L. donovani. It manifests through general symptoms, hepatosplenomegaly and pancytopenia in children younger than ten years old and immunocompromised adults. Case presentation: An 18-year-old female patient is admitted for evaluation, in the context of prolonged febrile syndrome, after successive respiratory intercurrents, weight loss, night sweats and arthromyalgias, with the onset 8 months before. When interviewing the patient, one travel to Valencia, in October 2023, was reported. General laboratory analysis and abdominal ultrasound investigations showed no alterations. However, a specific Western blot test for anti-L. infantum IgG antibodies, was positive. Under treatment with amphotericin B, symptoms resolved and the following PCR test was negative. Conclusions: Leishmaniasis was identified in a female patient without specific risk factors. The finding underlines the need for a closer collaboration with infectious disease specialists, depending on the clinical and epidemiological context.

Abstract: The appearance of new clinical manifestations (for example subcutaneous or skin abscesses) during anti-tuberculosis treatment is generally indicative of therapeutic failure. The cause of therapeutic failure may be the presence of a drug-resistant Mycobacterium infection or to the failure to achieve a sufficient concentration of the drugs in the bloodstream. Here we report the case of a 25-year-old man suffering from tuberculosis infection with lymph nodes and pulmonary involvement and an atypical response to specific therapy. Two weeks after starting the 4-drug antitubercular treatment, the patient began to experience fever, pain and functional impotence in the left foot and ankle with subsequent evidence of ankle and tarsal osteomyelitis. Later on, four weeks after starting treatment, the patient presented with several widespread painful subcutaneous abscesses on the trunk, back and right lower limb. Drainage was performed from the ankle and from one of the abscesses and the polymerase chain reaction (PCR) showed positive result for Mycobacterium tuberculosis in both samples with absence of resistance to drugs. Anti-tubercular medications were continued with resolution of the pulmonary and bone involvement but with persistence of subcutaneous abscesses, although subsequent drainages showed the absence of mycobacterium tuberculosis. We describe an unusual presentation of paradoxical reaction in the form of osteomyelitis and subcutaneous abscesses in an immunocompetent TB patient and we reported other similar cases of paradoxical reactions described in the literature in the last ten years, which demonstrate the importance of considering paradoxical reactions in patients who present with new or worsening signs and symptoms after starting tuberculosis treatment.

Abstract:

Oropouche fever is caused by the Oropouche virus (OROV; Bunyaviridae, Orthobunyavirus), one of the most frequent arboviruses that infect humans in the Brazilian Amazon. This year, an OROV outbreak was identified in Brazil, and its vertical transmission was reported, which was associated with fetal death and microcephaly. We describe the clinical manifestations identified in three cases of congenital OROV infection with confirmed serology (OROV-IgM) in the mother-newborn binomial. One of the newborns died, and post-mortem molecular analysis using real-time RT-qPCR identified the OROV genome in several tissues. All three newborns were born in the Amazon region in Brazil, and the mothers reported fever, rash, headache, myalgia, and/or retroorbital pain during pregnancy. The newborns presented with severe microcephaly secondary to brain damage and arthrogryposis, suggestive of an embryo/fetal disruptive process at birth. Brain and spinal images identified overlapping sutures, cerebral atrophy, brain cysts, thinning of the spinal cord, corpus callosum, and posterior fossa abnormalities. Fundoscopic findings included macular chorioretinal scars, focal pigment mottling, and vascular attenuation. The clinical presentation of vertical OROV infection resembled congenital Zika syndrome to some extent but presents some distinctive features on brain imaging and in several aspects of its neurological presentation. A recognizable syndrome with severe brain damage, neurological alterations, arthrogryposis, and fundoscopic abnormalities can be associated with in-utero OROV infection.

Abstract: Background/Objectives: Many Tropical diseases such as Malaria, Chagas, Human African Trypanosomiasis, and Lymphatic filariasis coexist in endemic countries, affecting more than 1 billion people worldwide, and are recognized as major global vector-borne diseases. Tackle this disease lies in a correct diagnosis, sensitive, specific, and fast. This study aims to describe and validate a new highly sensitive and specific multiple-analysis system that can effectively detect numerous etiological agents in a single test. Methods: A total of 230 human blood samples were evaluated retrospectively for parasite characterization and a total of 58 stool samples from Non-Human Primates (NHP). Results: The analytical specificity of the presented method was 100%, with no unspecific amplifications or cross-reactions with other blood parasitic diseases. The detection limit obtained was between 0.6 to 3.01 parasites/µl for Plasmodium species, 1,8 parasite/ml for Trypanosomatidae, and 2 microfilariae/ml in the case of Filariae. The sensitivity, specificity, predictive values, and kappa coefficient reached almost 100%, except for the sensitivity for Filariae, which dropped to 93,9%, and its NPV to 89.5%. The operational features described a turnaround and a hands-on time notably shorter than the compared methods with a lower cost per essay. Conclusions: This work presents a cost-effective and highly sensitive multiplexed tool (RT-PCR-bp) capable of performing a simultaneous detection for blood parasitic diseases using specific fluorescence probes, enabling the diagnosis of low parasite loads and co-infections.

Abstract:

Background/Objectives: This study aimed to evaluate the prevalence of viral agents identified by multiplex PCR in ARVI patients at Edirne Sultan 1. Murat State Hospital from April 2023 to April 2024, and to investigate the relationship between monthly average humidity and viral pos-itivity rates. Methods: The study included 764 adult patients (aged 18 and older) diagnosed with influenza symptoms. Respiratory viral samples were collected and analyzed using Multiplex PCR for COVID-19, Influenza A and B, and RSV, with results evaluated retrospectively. Group variability was assessed using SPSS version 22, employing chi-square and t-tests, with a significance level of p < 0.05. A stepwise multivariate logistic regression analysis for COVID-19 was also conducted. Results: COVID-19 PCR positivity was detected in 142 patients (18.6%), with INF-A in 13 (3.7%), INF-B in 15 (4.2%), and RSV in 2 (0.6%). Higher humidity was associated with reduced viral PCR positivity rates for COVID-19 and Influenza B, while lower humidity correlated with peak cases (p<0.05 for both). Stepwise logistic regression analysis indicated that high humidity levels offer protection against COVID-19 (OR: 0.356; 95% CI: 0.245-0.518). Conclusions: Our study provides essential epidemiological data by summarizing monthly virus distribution in our region, facilitating effective vaccine selection.

Abstract: Considering the sustained increase of dengue outbreaks in Latin America in recent years, this study proposes the use of machine learning (ML) tools with epidemiological data, meteorological climate parameters considering El Niño and La Niña (Niño 3.4 Index), and socioeconomic and demographic phenomena as a basis for the construction of an early warning system for dengue outbreaks in Zulia State, Venezuela. The study area covers 21 municipalities. Two ML models, support vector regression machine (SVM-R) and Gaussian process regression (GPR), were used. The data were used raw, standardised, and normalized for each model to be trained. The predictions of dengue outbreaks from the GPR and SVR algorithms show agreement with the dates of the real data; it was determined that there is a range of 2 to 3 weeks depending on the municipality. These coincide with previous studies showing that the algorithms do not work properly for some municipalities.

Abstract: Dengue in neonates is an infrequent yet significant cause of neonatal sepsis in endemic areas, often underdiagnosed due to its nonspecific clinical presentation and the lack of specific guidelines for this population. We present a series of three cases of neonatal dengue in patients with fever and signs of late-onset sepsis, who were initially treated with antibiotics without identifying a bacterial agent. Following the diagnosis of dengue through positive IgM, antibiotics were discontinued, and the patients showed favorable clinical outcomes with early hospital discharges. This study highlights the importance of considering dengue as a differential diagnosis in neonates with late-onset sepsis, which could help reduce unnecessary antibiotic use and its adverse consequences. We propose implementing a specific diagnostic algorithm for neonates in endemic regions, including the addition of serological and molecular testing for dengue, to improve management and outcomes in this population.

Abstract: Leishmaniasis is a serious infectious disease caused by Leishmania parasites, predominantly affecting tropical and subtropical regions. These parasites replicate within macrophages, manipulating the host immune response and facilitating infection progression. This study examined the expression profiles of long non-coding RNAs (lncRNAs), potential cis-target genes, and hub genes at different time points in human macrophages infected with Leishmania major. RNA-Seq analysis identified 39,828 lncRNAs, with 2,903 showing differential expression at one or more time points. As the infection progressed (4, 24, 48, and 72 hours), the number of up- and down-regulated lncRNAs gradually decreased. Six lncRNAs (lnc-UNC5D-8, lnc-TENM3-1, DIRC3-1, lnc-MTRNR2L12-10, lnc-FAM43A-6, and AKAP2-1) were consistently differentially expressed across all time points, potentially playing key roles in regulating the host immune response. Time-specific hub genes were also identified, regulating critical processes such as keratinization, epigenetic modifications, and immune responses. In particular, these genes were pivotal during the later stages of infection in maintaining tissue integrity and regulating immune responses. Early immune responses were dominated by immunoglobulin receptor activity and adaptive immune system activation. These findings highlight the critical roles of lncRNAs and hub genes in macrophage responses to Leishmania infection, offering potential targets for future therapeutic strategies.

Abstract: Antibiotic resistance is a global public health issue, largely driven by the misuse of these medications. This study aimed to compare the knowledge, attitudes and practices related to antibiotic use among students in Ecuador and Nigeria through a cross-sectional survey. The results indicated a strong understanding in both countries of the risks associated with inappropriate antibiotic use and the importance of completing prescribed treatments. However, significant differences were noted in the practice of self-medication, which was more prevalent in Ecuador. Additionally, behaviors such as insistence on obtaining antibiotics and the storing of leftover medications were common, underscoring the need for targeted educational interventions. The implications of these findings for promoting responsible antibiotic use are further discussed.

Abstract: Introduction: Patients receiving biological and targeted synthetic disease-modifying antirheumatic drugs (b/tsDMARDs) for rheumatological conditions are at an increased risk of serious, potentially life-threatening, infection. However, the incidence, aetiology and clinical course of serious infection in patients receiving b/tsDMARDs in tropical settings are incompletely defined. Methods: We retrospectively reviewed all patients with rheumatoid arthritis receiving b/tsDMARDs between October 2012 and October 2021, at Cairns Hospital in tropical Australia. The incidence, aetiology, and clinical course of serious infections (those requiring admission to hospital or parenteral antibiotics) was determined. Results: 310 patients had 1468 patient-years of b/tsDMARD therapy during the study period; 74/310 (24%) had 147 serious infections translating to an overall risk of 10.0 episodes of serious infection per 100-patient-years. The respiratory tract (50/147, 34%) and skin (37/147, 25%) were the most frequently affected sites. A pathogen was identified in 59/147 (40%) episodes and was most commonly Staphylococcus aureus (24/147, 16%). Only 2/147 (1%) were confirmed “tropical infections”: 1 case of Burkholderia pseudomallei and 1 case of mixed B. pseudomallei and community-acquired Acinetobacter baumannii infection. Overall, 13/147 (9%) episodes of serious infection required Intensive Care Unit admission (0.9 per 100-patient-years of b/tsDMARD therapy) and 4/147 (3%) died from their infection (0.3 per 100-patient-years of b/tsDMARD therapy). The burden of comorbidity and co-administration of prednisone were the strongest predictors of death or a requirement for ICU admission. Conclusion: The risk of serious infection in patients taking b/tsDMARDs in tropical Australia is higher than in temperate settings, but this is not explained by an increased incidence of traditional tropical pathogens.

Abstract: The combination of nanoemulgel and phytochemistry has resulted in several recent discoveries in the field of the topical delivery systems. The present study aimed to prepare turmeric (Curcuma longa) and neem (Azadirachta indica) based nanoemulgel against microbial infection as topical drug delivery. Olive oil (oil phase), Tween 80 (surfactant), and PEG600 (co-surfactant) were used for the preparation of nanoemulsion. Carbopol 934 was used as gelling agent to convert the nanoemulsion to nanoemulgel and promote to control the release of biological properties of turmeric and neem. The nanoemulsion were characterized based on particle size distribution, PDI values and compatibility using FTIR analysis. In contrast, the nanoemulgel was evaluated based on pH, viscosity, spreadability, plant extract and excipients compatibility or physical state, in-vitro study, ex-vivo mucoadhesive study, antimicrobial properties and stability. The resulting nanoemulsion was homogeneous, stable during the centrifugation process, with the smallest droplets and low PDI values. FTIR analysis also confirmed good compatibility and absence of phase separation between the oil substance, surfactant, co-surfactant with both plant extracts. The improved nanoemulgel also demonstrated a smooth texture, good consistency, pH, desired viscosity, ex-vivo mucoadhesive strength with highest spreadability, and an 18-hour in-vitro drug release study. Additionally, it exhibited better antimicrobial properties against different microbial strain. Stability studies also revealed that the product had good rheological properties and physicochemical state for a period of over 3 months. The present study has affirmed that turmeric and neem based nanoemulgel as a promising alternative for microbial infection particularly associated by microorganisms via topical application.

Abstract: Doravirine (DOR) is a non-nucleoside reverse transcriptase inhibitor (NNRTI) with efficacy against some NNRTI resistant mutants. Although DOR resistance mutations are established for HIV-1 subtype B, it is less clear for non-B subtypes. This study investigated prevalent NNRTI resistance mutations on DOR susceptibility in HIV-1 subtype C. Prevalent drug resistance mutations were identified from a South African genotypic drug resistance testing database. Mutations, single or in combination, were introduced into replication defective pseudoviruses and assessed for DOR susceptibility in vitro. The single V106M and Y188L mutations caused high-level resistance while others didn’t significantly impact DOR susceptibility. We observed agreement between our in vitro and the Stanford HIVdb predicted susceptibilities. However, the F227L mutation was predicted to cause high-level DOR resistance but was susceptible in vitro. Combinations of mutations containing K103N, V106M or Y188L caused high-level resistance, in agreement with the predictions. These mutations are frequently observed in patients failing efavirenz or nevirapine-based first-line regimens. However, they are also observed in those failing a protease inhibitor-based second-line regimen, as we have observed in our database. Genotypic drug resistance testing is therefore vital prior to initiation on DOR-based treatment for those previously exposed to efavirenz or nevirapine.

Abstract: Necroptosis is a regulated form of cell death implicated in several pathological conditions, in-cluding viral infections. In this study, we investigated the expression and correlation of necroptosis markers, MLKL, RIP1 and RIP3, in human liver tissue from fatal cases of yellow fever (YF) using immunohistochemistry (IHC). Liver samples were obtained from 21 YF-positive individuals and five flavivirus-negative controls with preserved liver parenchymal architecture. The cases un-derwent histopathological analysis, followed by tissue immunostaining with the immuno-histochemical method of streptavidin-biotin peroxidase. Using the in situ method, we evaluated the centrilobular (Z3), midzonal (Z2), periportal zone and portal tract (PT) zones of human liver parenchyma with markers for necroptosis, RIPK1, RIPK3 and MLKL. Quantitative analysis re-vealed significantly higher expression of MLKL, RIP1 and RIP3 in the liver parenchyma of YF cases compared to controls in different zones (Z3, Z2, Z1) and portal tracts (PT) of the liver, especially in zone 2. Immunostaining confirmed the localization of MLKL, RIP1 and RIP3 in hepatocytes and inflammatory infiltrates, highlighting their involvement in the pathogenesis of YF. Pearson's correlation analysis demonstrated significant correlations between necroptosis markers which indicate their coordinated regulation during YF-induced liver injury.

Abstract: Cestodes are etiological agents of neglected diseases such as echinococcosis and cysticercosis, which are major public health problems. Antiparasitic treatment relies on a small number of approved drugs, which are often only partially effective, poorly tolerated and require prolonged administration. Thus, the discovery of novel potential treatments is critical. The Stevia genus (Asteraceae) includes species that are associated with medicinal uses and are considered a source of bioactive compounds. Here, we analyzed four South American Stevia species that have previously demonstrated antiprotozoal properties. The effect of dichloromethane extracts of these species was determined by motility assays on Mesocestoides vogae, a laboratory model of cestodes. Stevia alpina showed the highest anthelmintic potential followed by S. maimarensis and S. multiaristata, while S. aristata was the least active. The sesquiterpene lactones estafietin and eupatoriopicrin were purified from S. alpina and S. maimarensis, respectively. Estafietin showed cestocidal activity, inhibiting parasite viability in a dose-dependent manner, even from the first day of incubation. Consistent with the motility effects, the extract of S. alpina and estafietin induced major alterations on the morphology of the parasite. The results of this report show that Stevia species represent a source of new molecules with potential for the treatment of neglected tropical diseases caused by cestodes.

Abstract: (1) Background: Plasmodium vivax causes the largest malaria burden in Brazil, and chloroquine resistance poses a challenge to eliminating malaria by 2035. Illegal mining in the Roraima Yanomami indigenous territory can lead to the introduction of resistant parasites. This study aimed to investigate mutations in the pvcrt-o and pvmdr-1 genes to determine their potential as predictors of P. vivax chloroquine-resistant phenotypes. (2) Methods: Samples were collected in two health centers of Boa Vista. A questionnaire was completed, and blood was drawn from each patient. Then, DNA extraction, PCR, amplicon purification, and DNA sequencing were performed. After alignment with the Sal-1, the amplified fragment was analyzed. Patients infected with the mutant parasites were queried in the Surveillance Information System. (3) Results: 98% (157/164) of participants were from illegal mining areas. The pvcrt-o was sequenced in 151 samples, and the K10 insertion was identified in 13% of them. The pvmdr1 was sequenced in 80 samples: the MYF haplotype (958M) was detected in 92% of them, the TYF in 8%, while MYL was absent. No cases of recrudescence, hospitalization, or death were found. (4) Conclusions: Mutations in the pvcrt-o and pvmdr-1 genes have no potential to predict chloroquine resistance in P. vivax.

Abstract: Basophils are initiators of the Th2 response related to the progression of canine visceral leishmaniasis (CanL). Miltefosine has been presented as an alternative in treatment due to its leishmanicide and immunomodulatory effects. Many blood cells have been used as predictive biomarkers, but none of them focused on the immunomodulatory action of miltefosine in the different stages of the disease. Identifying the predictive hematological biomarkers in dogs with visceral leishmaniasis treated with miltefosine. The animals were divided into three groups: sick dogs; infected dogs, dogs exposed. The animals were submitted to differential blood cell count and CanL diagnosis, through DPP, ELISA and qPCR. The groups were monitored from the time zero (T0) before treatment, and the times twenty (T20) and thirty (T30) days after the beginning of treatment using miltefosine at a dose of 1mL/10kg per day for 28 days. Basophils showed an exponential increase in the infected and sick group with an increase of IgG, suggesting a Th2 response. In the exposed group there was reduction of basophils with increase in monocytes and IgG reduction, suggesting a Th1 response. We suggest basophils as a predictive biomarker of immunomodulation in the treatment of CanL with miltefosine.

Abstract: Background: Leishmaniasis is a significant global public health issue that is caused by parasites from Leishmania genus. With limited treatment options and rising drug resistance, there is a pressing need for new therapeutic approaches. Molecular chaperones, particularly Hsp90, play a crucial role in parasite biology and are emerging as promising targets for drug development. Objective: This study evaluates the efficacy of 17-DMAG in treating BALB/c mice from cutane-ous leishmaniasis through in vitro and in vivo approaches. Materials and Methods: We assessed 17-DMAG cytotoxic effect on bone marrow-derived mac-rophages (BMMΦ) and its effects against L. braziliensis promastigotes and intracellular amastigotes. Additionally, we tested the compound's efficacy in BALB/c mice infected with L. braziliensis via intraperitoneal administration to evaluate the reduction of lesion size and de-crease of parasite load in the ears and lymph nodes of infected animals. Results: 17-DMAG showed selective toxicity [selective index=432) towards Leishmania amastigotes, causing minimal damage to host cells. The treatment significantly reduced lesion sizes in mice and results in parasite clearance from ears and lymph nodes. It also diminished in-flammatory responses and reduced the release of pro-inflammatory cytokines (IL-6, IFN-g, TNF) and the regulatory cytokine, IL-10, underscoring its dual leishmanicidal and anti-inflammatory properties. Conclusion: Our findings confirm the potential of 17-DMAG as a viable treatment for cutaneous leishmaniasis and support further research into its mechanisms and potential applications against other infectious diseases.

Abstract: Regardless of the SARS-CoV-2 pandemic containment, it remains paramount to comprehensively understand its underlying mechanisms to mitigate potential future health and economic impacts, comparable to those experienced throughout the course of the pandemic. The angiotensin-converting enzyme 2 (ACE2) provide anchorage for SARS-CoV-2 binding, thus implicating that ACE and ACE2 might contribute to the variability in infection severity. This study aimed to elucidate predisposing factors influencing the disease course among people infected by SARS-CoV-2, focusing on angiotensin-converting enzyme (ACE) and ACE2 polymorphisms. Notably, despite similar demographics and comorbidities, COVID-19 patients exhibit substantial differences in prognosis. Genetic polymorphisms in ACE and ACE2 have been implicated in disease progression, prompting our investigation into their role in COVID-19 evolution. Using next-generation sequencing (NGS), we analyzed ACE and ACE2 genes in a sample group comprising six subjects infected by SARS-CoV-2. Our findings revealed a correlation between specific polymorphisms and COVID-19 outcomes. Specifically, ACE and ACE2 intronic deletions were observed in all deceased patients, suggesting a potential association with mortality. These results highlight the significance of genetic factors in shaping the clinical course of COVID-19, emphasizing the importance of further research into the impact of genetic variations on COVID-19 severity.