Abstract: Metacyclogenesis is a critical process during Trypanosoma cruzi life cycle. This transition naturally occurs in the insect vector’s gut, influenced by temperature, nutrient availability and pH fluctuations, among others. Triatomine Artificial Urine (TAU) medium is the widely adopted approach to metacyclogenesis in vitro. However, this becomes less effective when epimastigotes are cultured for long periods, limiting the study of the metacyclic trypomastigote stage. We aimed to establish a practical and efficient method for generating high concentrations and purity of metacyclic epimastigotes in vitro. Epimastigotes of the Dm28c strain were exposed to pH shifts in nutrient-rich (MT-LIT) and nutrient-poor (M16) media, under static or agitated conditions. Results showed that both media promoted higher metacyclogenesis rates than TAU, with epimastigotes adherence to the substrate being crucial factor. Metacyclogenesis efficiency varies depending on the strains and culture conditions. LIT and M16 at pH 6 produced metacyclic trypomastigotes with infective capacity on Vero cells. Under these conditions, a variety of intermediate forms were observed compared to those induced by TAU metacyclogenesis. Our findings further emphasize the strain-dependent nature of optimal in vitro metacyclogenesis conditions and offer new opportunities for studying the intermediate forms involved in this essential process.

Abstract:

The COVID-19 pandemic showcased the power of genomic surveillance in tracking infectious diseases, driving rapid public health responses and global collaboration. This same infrastructure is being leveraged for malaria molecular surveillance (MMS) in Africa to tackle challenges like artemisinin partial resistance and Plasmodium falciparum histidine-rich protein 2 and 3 gene deletions. However, variability in sequencing methods and data reporting is currently limiting the validation, comparability, and reuse of data. To maximize the impact of MMS, we propose minimal and optimal data for reporting that maximize transparency and FAIR (Findable, Accessible, Interoperable, Reusable) principles. Rather than focusing on specific data formats, here, we propose what should be reported and why. Moving to reporting individual infection-level allele or microhaplotype data is central to maximizing impact of MMS. Reporting must adhere to local regulatory practices and ensure proper data oversight and management, preventing data colonialism and preserving opportunities for data generators. With malaria’s challenges transcending borders, reporting and adopting standardized practices is essential to advance research and strengthen global public health efforts.

Abstract:

Colpodella species are free-living predatory protists that prey on algae, ciliates and bodonids using myzocytosis. Colpodella species have been reported in human and animal infections. Polymerase chain reaction (PCR) using primers targeting 18S rRNA genes of Cryptosporidium and piroplasms has identified Colpodella species in arthropods, host blood, and feces demonstrating the phylogenetic closeness of Colpodella species to the apicomplexa. However, in both human and animal infections, life cycle stages of Colpodella present in arthropods and infected hosts are unknown. In this review we provide an overview of widespread occurrence of Colpodella species in ticks, and pathogenicity in humans and animals. We discuss methods for culture and microscopy that can aid diagnosis. Phylogenetic tree analysis of Colpodella species identified using 18S rRNA demonstrates that the Colpodella species identified in different geographic regions represent different species and strains that may impact virulence and zoonotic transmission. There is a pressing need to culture Colpodella species, and to stain cells for morphological identification. This will aid molecular investigations aimed at identifying molecular markers of Colpodella spp. facilitating transmission, survival and pathogenesis in hosts, and determining which species and strains to prioritize for the risk of zoonotic infections to humans and for infections in animals.

Abstract: The resistance of small ruminants to synthetic anthelmintics and helminthosis poses considerable challenges to global livestock production. Integrating biological control with nematophagous fungi, particularly Duddingtonia flagrans, is crucial in addressing worm infestations. Although effective in experiments, the absence of a commercial product has been a limitation. The introduction of Bioverm®, the first commercial product using D. flagrans in Brazil, marks a significant advancement. This study on a Brazilian sheep farm evaluated a 167-day Bioverm® treatment, following moxidectin application, focusing on eggs per gram of feces (EPG), FAMACHA score (SCORE) and sheep weight (WEIGHT). Statistical results showed marked improvements in all parameters after 80 days with Bioverm®. EPG values gradually declined, demonstrating successful biological control, while SCORE increased steadily, stabilizing after 130 days. Minor weight changes indicated effective nutritional management. These outcomes suggest Bioverm® significantly reduces dependence on chemical anthelmintics and addresses resistance issues. D. flagrans thus emerges as a promising tool for managing nematode infestations without negatively impacting animal weight. This research enhances the understanding of Bioverm®'s role, confirming its practicality as a viable alternative for helminth control in varied environments, thereby reinforcing its strategic importance in livestock management.

Abstract:

Vector-borne parasitic diseases represent a critical public health challenge in Africa, disproportionately impacting vulnerable populations and linking human, animal, and environmental health through the One Health framework. In this review we explore the epidemiology of these diseases, particularly those that are underreported and highlight the complex transmission dynamics involving domestic and wild animal hosts. Climate change, urbanization, and deforestation exacerbate the emergence and reemergence of arthropod-borne parasitic diseases like malaria, leishmaniasis, and trypanosomiasis, complicating control and disease elimination efforts. Despite progress in managing certain diseases, gaps in surveillance and funding hinder effective responses, allowing many arthropod zoonotic parasitic infections to persist unnoticed. The increased interactions between humans and wildlife, driven by environmental changes, heighten the risk of spillover events. Leveraging comprehensive data on disease prevalence, distribution, and vector ecology, coupled with a One Health approach, is essential for developing adaptive surveillance systems and sustainable control strategies. This review emphasizes the urgent need for interdisciplinary collaboration among medical professionals, veterinarians, ecologists, and policymakers to effectively address the challenges posed by vector-borne parasitic diseases in Africa, ensuring improved health outcomes for both humans and animals.

Abstract: Cysticercosis is a serious zoonotic parasitic disease caused by the larval cysts of Taenia solium parasitizing humans or pigs. The immune pathogenesis of this disease is currently unclear. Preliminary studies found that the thioredoxin peroxidase (TPx) protein in the excretory-secretory antigens (ESA) of the cysticercus cellulosae can induce T-cell immune imbalance in piglets, leading to a Th2-type immune response. In this study, flow cytometry revealed that TPx protein can induce Th1 cells differentiation within 24 hours and Th2 cells differentiation within 48 hours. Further analysis of the different transcriptomes after TPx protein treatment of Jurkat T cells suggested that TPx protein may induce host Th1/Th2 cells imbalance through the janus kinase/signal transducer and activator of transcription (JAK/STAT) signaling pathway. Western blot results indicated that treatment with TPx protein for 48 hours significantly increased the expression of p-JAK3, p-STAT6, and GATA3 proteins. Interestingly, after using a JAK3 inhibitor, the expression level of the Th1 transcription factor TBX21 significantly increased, indicating that after inhibiting Th2 cells differentiation, T cells tend to differentiate toward the Th1 cells direction. In summary, the JAK/STAT signaling pathway plays a key role in the cysticercus cellulosae TPx protein induced Th1/Th2 cells imbalance, providing important scientific evidence for elucidating the immune pathogenesis of cysticercosis and vaccine development.

Abstract: The advancement of multi-omics technologies is crucial to deepen knowledge on tick biology. These approaches, used to study diverse phenomena, are applied to experiments that aim to understand changes in gene transcription, protein function, cellular processes, and prediction of systems at global biological levels. This review addressed the application of omics data to investigate and elucidate tick physiological processes, such as feeding, digestion, reproduction, neuronal, endocrine systems, understanding population dynamics, transmitted pathogens, control, and identifying new vaccine targets. Furthermore, new therapeutic perspectives using tick bioactive molecules, such as anti-inflammatory, analgesic, and antitumor were summarized. Taken together, the application of omics technologies can help to understand the protein functions and biological behavior of ticks, as well as the identification of potential new antigens influencing the development of alternative control strategies and consequently the tick borne-diseases prevention in veterinary and public health contexts. Finally, tick population dynamics have been determined by a combination of environmental factors, host availability and genetic adaptations, and recent advances in omics technologies have improved our understanding of their ecological resilience and resistance mechanisms. Future directions point to the integration of spatial omics and artificial intelligence to further unravel tick biology and improve control strategies.

Abstract: Background: Microsporidia MB (MB), a promising biological control agent suppresses Plasmodium falciparum transmission in Anopheles mosquitoes. Methods: This study examined the spatial distribution of MB infection in natural populations of An. gambiae s.l. mosquitoes collected in Nigeria and Niger Republic, and its potential modulation of insecticide susceptibility in the Anopheles mosquitoes. Results: The overall prevalence of MB in F₀ mosquitoes was 12.25% (95% CI: 7.76%-16.75%); 25 mosquitoes out of 204 were positive. Geographic variation was observed, with a higher prevalence (5/15 mosquitoes) in Ebonyi State (33.33%, 95% CI: 9.48%-57.19%, Fisher's exact test, p = 0.008). Infection rates were higher in An. coluzzii mosquitoes (21/133 mosquitoes), estimated at 15.79% (95% CI: 9.59%-21.99%) compared to An. gambiae s.s. mosquitoes (4/67), approximately 5.63% (95% CI: 0.27%-11.00%), χ² = 4.44; df = 1, p = 0.035)]. Resistant mosquitoes had a significantly higher prevalence of MB infection at 28.57% (95% CI: 16.74%-40.40%) and OR of 3.33 (95% CI: 1.23-9.03, p = 0.017) compared with susceptible mosquitoes. Conclusion: MB has wide geographic distribution across Nigeria and Niger Republic. An. coluzzii and resistant mosquitoes are more infected with this fungi. Understanding the geographic and species-specific infection patterns and implication in insecticide resistance could guide targeted vector control strategies using this biological agent.

Abstract: Leishmaniases are zoonotic vector-borne diseases caused by a wide variety of Leishmania species with complex transmission cycles involving different reservoirs, potential new hosts and vectors. Similarly, to other eukaryotes, Leishmania release extracellular vesicles (LEVs) to play important initial interactions that are crucial to modulate the subsequent systemic immune response on the establishment of infection in humans and others hosts like dogs. Recent studies in endemic areas of Brazil concluded that canine infections were predominantly due to L. amazonensis and not restricted to L. infantum (syn. Leishmania chagasi). Under these premises, the diagnosis of leishmaniasis needs to be improved with the identification of current etiological agent and the histopathologic features, highlighting the differential diagnosis and the molecular components of LEVs. In this way, the dual aim of that study is to register collected observations of natural canine infections, enhancing the relevance of differential diagnosis in companion animals and inserting in vitro results in the field of LEVs that still research gaps to be filled to understand the mechanisms and biological aspects involving the parasite-host interactions. Therefore, improve these studies of Parasitology research is important for diagnostic, prognostic, treatment advances and continuing need for global prevention, control, elimination/eradication of these parasitic infections.

Abstract: Despite the existence of therapeutic and prophylactic measures, gastrointestinal parasites are common in pets. Due to the zoonotic potential of some species, parasitic protozoa and helminths are of great importance to public health. In this study, we investigated the occurrence of the main gastrointestinal parasites in domestic dog puppies in the city of Araçatuba, São Paulo, Brazil. One hundred fecal samples were collected from dogs up to six months of age. Parasites were diagnosed using three methods; Willis’, Faust's and malachite green coproparasitological techniques. Parasite prevalence as determined by Willis and/or Faust diagnostic techniques was as follows: Toxocara spp. 34%, Isospora spp. 28%, Ancylostoma spp. 22% and, Giardia spp. 8%. These prevalence rates were calculated by considering an animal to be positive if Willis’ or Faust’s, or both tests returned a positive result. Diagnosis with malachite green was negative for all samples. Infection with Toxocara spp., the most prevalent pathogen in this survey, was not limited to dogs with abnormal fecal consistency. The occurrence of asymptomatic parasitized dogs increases the risk of zoonotic transmission.

Abstract: Hookworm infections affect 500-700 million people worldwide and can lead to chronic conditions such as malnutrition and anemia. The challenge of managing these infections is heightened by the absence of effective vaccines and the potential for anthelmintic resistance to develop. A comprehensive understanding of the molecular interactions between parasite and host is vital for unraveling the complexities of infection dynamics. This study aimed to identify immune system components responsible for host specificity in hookworms by infecting immunodeficient mouse models. Findings herein indicate that innate immunity is essential in protecting against Ancylostoma ceylanicum establishment in mice. Significant differences in parasite development were noted in mice lacking the signal transducer and activator of transcription 6 (Stat6-), with female mice reliant on this Th2 pathway for protection. Secondary infections in female Stat6- mice and an immunodeficient NSG mouse reached patency, demonstrating that immunodeficient mice fail to develop protective immunity against subsequent infections, similar to human hookworm infections. In contrast, no parasite development was observed in mice infected with A. caninum, highlighting that this species survival strategies are independent of host immune landscape. These results underscore the complexity of host-parasite interactions and point to new directions for therapeutic strategies, which may differ between sex.

Abstract:

Camel production is used for a variety of reasons in East Africa. Camels therefore play a significant role in Somali culture, society, and the economy. The Somali economy is largely dependent on livestock, and camels are a major source of income. Camels are shipped to the Middle East, as are their prized milk and meat. With an estimated seven million, Somalia is home to more camels than perhaps any other nation in the world. Investigations were carried out to look at some Platyhelminthes lesions in the liver of camels with the purpose of both Gross and histopathological lesions at some meat companies in Somalia. Studies were conducted from April 2024 to October 2024. A total sample of 340 Livers originated from slaughtered camels at some meat in Dynile District. However, out of 200 liver Organs were examined with gross and histological lesions for further tests in Salaam University Laboratory, Faculty of Veterinary Medicine, and University of Nairobi Department of Veterinary Pathology. Microbiology and Parasitology Nairobi Kenya. In this study, 84.5% (n=200) of the most cases of Platyhelminthes were Taenia saginata, Fasciola hepatic, and Liver flukes followed by Haemorrhages, Congestion, Oedema, and hydatidosis. The histological features included Tissue Infiltration, Lymphocytic infiltration, Granulomas, Necrosis, Fibrosis, and inflammation. Those results indicated major health problems with one health approach and Zoonotic aspects in humans and animals.

Abstract:

Faced with the increased frequency of zoonotic spillover in recent decades, emerging vector-borne diseases from non-human primates pose a significant threat to global public health. Understanding transmission dynamics driven by arthropod vectors between wildlife populations is critical for surveillance, modelling and mitigation. Elevated canopy-level sampling is a valuable approach for elucidating vector behaviour and sylvatic transmission. However, this is underutilized in many regions due to the logistical and mechanical challenges of re-purposing ground-based trapping for the forest canopy. We review methods of canopy-level entomological surveillance, present case studies and identify opportunities to integrate new technologies. Paired with robust experimental design, canopy-level trapping can complement existing surveillance of emerging zoonotic diseases and provide critical insights into the role of vectors driving spillover risks.

Abstract:

The polyamine pathway in Leishmania parasites has emerged as a promising target for therapeutic intervention, yet the functions of polyamines in parasites remain largely unexplored. Ornithine decarboxylase (ODC) and spermidine synthase (SPDSYN) catalyze the sequential conversion of ornithine to putrescine and spermidine. We previously described that Leishmania donovani Δodc and Δspdsyn mutants exhibit markedly reduced growth in vitro and diminished infectivity in mice, with the effect being most pronounced in putrescine-depleted Δodc mutants. Here, we report that in polyamine-free media, ∆odc mutants arrested proliferation and replication, while ∆spdsyn mutants showed a slow growth and replication phenotype. Starved ∆odc parasites also exhibited a marked reduction in metabolism, which was not observed in the starved ∆spdsyn cells. In contrast, both mutants displayed mitochondrial membrane hyperpolarization. Hallmarks of apoptosis, DNA fragmentation and membrane modifications, were observed in Δodc mutants incubated in polyamine-free media. These results show that putrescine depletion had an immediate detrimental effect on cell growth, replication, and mitochondrial metabolism and caused an apoptosis-like death phenotype. Our findings establish ODC as the most promising therapeutic target within the polyamine biosynthetic pathway for treating leishmaniasis.

Abstract: Myxobolus species are Myxosporean parasites affecting various fish, causing diseases that weaken populations and result in substantial economic losses in aquaculture and fisheries. Despite extensive studies in Asia, Europe, and the Americas, there is limited research on Myxobolus in Africa, particularly in Tanzania, where fisheries and aquaculture are vital. This study investigated the prevalence and genetic characteristics of Myxobolus parasites in 384 fish samples from Dar es Salaam (Indian Ocean) and Mwanza (Lake Victoria). Samples were examined for cysts and spores using microscopy, followed by molecular characterization through PCR amplification of the 18S rDNA gene, Sanger sequencing, phylogenetic analysis, and genetic distance evaluation. The overall prevalence of Myxobolus was 12%, with a significantly higher prevalence in Mwanza (21.88%) compared to Dar es Salaam (6.25%). Statistical analysis revealed significant associations between prevalence, fish species, and locality. Phylogenetic analysis identified two genetic lineages within a monophyletic group, clustering with Myxobolus species from Israel, Egypt, and Ghana, suggesting potential novel species. Genetic distance analysis indicated greater variation in saltwater samples compared to freshwater. These findings highlight the higher prevalence of Myxobolus in freshwater and emphasize the need for targeted management strategies, continued surveillance, and research to safeguard fish populations and sustain aquaculture.

Abstract: Ichthyophthirius multifiliis, a parasitic ciliate, causes "white spot disease" in freshwater fish and poses a significant threat to global freshwater aquaculture. To eliminating the free-swimming theront stage from the aquaculture environment is a critical measure for controlling I. multifiliis infections. The natural predator of I. multifiliis theronts in fish-farming ponds were identified using fluorescent dye-labelled live theronts and quantitative PCR; meanwhile, the zooplankton community composition in the positive ponds of I. multifiliis detected by quantitative PCR, were analyzed by eDNA metabarcoding assay. The results revealed that predation on theronts by cyclopoid copepods, in-cluding Cyclops vicinus, Thermocyclops taihokuensis, Cyclops sp., Thermocyclops sp., Eucyclops sp., and Mesocyclops sp. from the in-situ predation aquatic ecosystem, and among these copepods, C. vicinus was identified as a natural dominant predator of I. multifiliis in spring and winter. This study provides a scientific basis for further exploration and utilization of natural predators to enhance sustainable and environmentally friendly control strategies against I. multifiliis.

Abstract: Spectrum of ixodid ticks that bite people in Western Siberia significantly changed over the past two decades. In this study, we determined tick species attacking people in surroundings of Novosibirsk and the range of bacterial agents they infected with. This study included 301 ticks taken from people and 46% were Ixodes pavlovsky, followed by Ixodes persulcatus (19.6%), I. persulcatus / I. pavlovskyi interspecies hybrids (19.6%), and Dermacentor reticulatus (12.8%). Human DNA was determined in ticks, first demonstrating that all these tick species, including hybrids, were able effectively feed on humans. DNA of Borrelia spp., Rickettsia spp. and Anaplasmatacreae bacteria was detected in different tick species. Borrelia garinii prevailed in Ixodes species, being found in 8.8% ticks, whereas B. afzelii and B. bavariensis were found in single ticks. Borrelia miyamotoi was revealed in 3.7% ticks. Among Rickettsia spp., “Candidatus Rickettsia tarasevichiae” and R. raoultii were identified mainly in I. persulcatus and D reticulatus (44.8% and 26.3%, respectively), whereas Rickettsia helvetica was found only in 2.2% I. pavlovsky. The prevalence of Anaplasma phagocytophilum, Ehrlichia muris and Neoehrlichia mikurensis did not exceed 2%. The obtained results indicate a high risk for humans to be infected with agents of Lyme borreliosis, primarily B. garinii.

Abstract: Two related P-type ATPases designated as ATPase1 and ATPase3 have been identified in Plasmodium falciparum. These two ATPases exhibit very similar gene and protein structures and are most similar to P5B-ATPases. There are some differences in the predicted substrate-binding sites of ATPase1 and ATPase3 which suggest different functions for these two ATPases. Orthologues of ATPase3 were identified in all Plasmodium species including the related Hepatocystis and Haemoproteus. ATPase3 orthologues could also be identified in all apicomplexan species, but no clear orthologues were identified outside of the Apicomplexa. In contrast, ATPase1 orthologues were only found in the Laverania, avian Plasmodium species, and Haemoproteus. ATPase1 likely arose from a duplication of the ATPase3 gene early in the evolution of malaria parasites. These results support a model in which early malaria parasites split into two clades. One clade consists of mammalian malaria parasites and Hepatocystis but excludes P. falciparum and related Laverania. The other clade includes Haemoproteus, avian Plasmodium species, and Laverania. This contrasts to recent models which suggest all mammalian malaria parasites form a phylogenetic group and all avian malaria parasites form a separate phylogenetic group. ATPase1 may be a useful taxonomic/phylogenetic character for the phylogeny of Haemosporidia.

Abstract: tRNA molecules are among the most fundamental and evolutionarily conserved RNA types, primarily facilitating the translation of genetic information from mRNA into proteins. Beyond their canonical role as adaptor molecules during protein synthesis, tRNAs have evolved to perform additional functions. One such non-canonical role for tRNAs is through the generation of tRNA-derived fragments via specific cleavage processes. These tRNA-derived small RNAs (tsRNAs) are present across all three domains of life, including in protozoan parasites. They are formed through the cleavage of the parent tRNA molecules at different sites, resulting in either tRNA halves or smaller fragments. The precise mechanisms underlying the synthesis of various tRNA-derived fragments, including the specific RNases involved, as well as their distinct functions and roles in parasite physiology, are not yet fully understood and remain an active area of ongoing research. However, their role in modulating gene expression, particularly during stress responses, is becoming increasingly evident. In this context, we discuss recent findings on the roles of tRNA-derived small RNA in various protozoan parasites. Furthermore, we investigate how these tsRNAs either modulate gene expression within the parasite itself or are packaged into extracellular vesicles to alter host gene expression, thereby promoting parasite survival and adaptation.

Abstract:

Colpodella species are predatory biflagellates phylogenetically related to pathogenic Apicomplexans like Plasmodium spp., Cryptosporidium spp., Babesia spp. and Theilaria spp. Colpodella species have been reported in human and animal infections. Trophozoites of Colpodella sp. ATCC 50594 obtain nutrients through myzocytosis and endocytosis. Following attachment of Colpodella sp. to its prey Parabodo caudatus, cytoplasmic contents of the prey are aspirated into a posterior food vacuole that initiates encystation. Unattached trophozoites also endocytose nutrients as demonstrated by the uptake of 40 and 100 nm nanoparticles. Cytochalasin D treatment was shown to distort the tubular tether formed during myzocytosis showing that actin plays a role in myzocytosis. Markers associated with myzocytosis, endocytosis and food vacuole formation are unknown. Furthermore, the relationship between the model Colpodella sp. ATCC 50594 and Colpodella sp. identified in arthropods, human and animal hosts are unknown. In this study we investigated the conservation of the coronin and Kelch 13 genes in Colpodella sp. ATCC 50594 using polymerase chain reaction (PCR). Kelch 13 distribution in Colpodella sp. ATCC 50594 life cycle stages was investigated using anti-Kelch 13 antibodies by immunofluorescence and confocal microscopy. Both genes were amplified from genomic DNA extracted from diprotist culture containing Colpodella sp. and P. caudatus but not from monoprotist culture containing P. caudatus alone. We amplified DNA encoding 18s rRNA with similarity to 18s rRNA amplified using piroplasm primers from the Italian Colpodella sp. identified in cattle and ticks. Detection of the coronin and Kelch genes in Colpodella sp. provides for the first time markers for actin binding and endocytosis in Colpodella species that can be investigated further to gain important insights into the mechanisms of myzocytosis, endocytosis and food vacuole formation in Colpodella sp.