Parasite最新文献

In the last few years, the number of studies on feline hepatozoonosis has increased, but our knowledge on the actual species of Hepatozoon and/or different genotypes affecting felines is still incipient. At least three species, namely Hepatozoon felis, H. canis, and H. silvestris, have been isolated from domestic cats in various countries. Additionally, there are indications that other species and genotypes may affect felines in given geographic areas. This study was carried out to investigate the occurrence of Hepatozoon spp. in cats from Niterói, a municipality within the metropolitan area of Rio de Janeiro, Brazil. Individual blood samples were collected from 28 cats enrolled in a spaying/castration program. DNA was extracted from all samples and subjected to sequencing specific for Hepatozoon spp. DNA of H. felis was found in 21/28 cats (75%), and four genetic polymorphisms never described thus far were detected. This is the first report of H. felis in cats living in the State of Rio de Janeiro, and the present data confirm that H. felis is a species complex encompassing different genotypes circulating within cat populations. Further studies are warranted to investigate whether different genotypes have different biology or pathogenicity for felids.

Autoimmune diseases are characterized by dysregulated immunity against self-antigens. Current treatment of autoimmune diseases largely relies on suppressing host immunity to prevent excessive inflammation. Other immunotherapy options, such as cytokine or cell-targeted therapies, have also been used. However, most patients do not benefit from these therapies as recurrence of the disease usually occurs. Therefore, more effort is needed to find alternative immune therapeutics. Schistosoma infection has been a significant public health problem in most developing countries. Schistosoma parasites produce eggs that continuously secrete soluble egg antigen (SEA), which is a known modulator of host immune responses by enhancing Th2 immunity and alleviating outcomes of Th1 and Th17 responses. Recently, SEA has shown promise in treating autoimmune disorders due to their substantial immune-regulatory effects. Despite this interest, how these antigens modulate human immunity demonstrates only limited pieces of evidence, and whether there is potential for Schistosoma antigens in other diseases in the future remains an unsolved question. This review discusses how SEA modulates human immune responses and its potential for development as a novel immunotherapeutic for autoimmune diseases. We also discuss the immune modulatory effects of other non-SEA schistosome antigens at different stages of the parasite's life cycle.

Sentinel surveillance plays a critical role in monitoring pathogen circulation, assessing potential threats for species conservation, and evaluating the risk of spillover to human populations. This study provides a comprehensive exploration of helminth parasites in the Mediterranean-distributed hedgehog species Atelerix algirus in Mallorca, Balearic Islands. Using an integrated approach that combines necropsies and morphological and molecular identifications using the COI gene, we identified 11 helminth taxa in 135 hedgehogs, representing half of those that died at the local wildlife hospital in Mallorca between 2019 and 2022. We report an overall A. cantonensis prevalence of 11.5% and confirm the first case of a subclinical neuroangiostrongyliasis infection in a wildlife host. Infection prevalences over the year revealed that only two species, the nematode A. cantonensis and the cestode Mathevotaenia sp., had a seasonal pattern, with most A. cantonensis cases occurring in autumn and, to a lesser extent, Mathevotaenia sp. cases in winter. This pattern is probably due to the higher abundance and greater activity of snails and slugs (intermediate hosts) during these seasons, with important implications for public health and strategies for prevention of neuroangiostrongyliasis. Other key findings include a high prevalence (88.1%) of the lungworm Crenosoma striatum and detection of the acanthocephalan Moniliformis saudi for the first time in A. algirus. We anticipate that our study will facilitate surveillance efforts and clarify species identities in future studies. Given the lethal effects of A. cantonensis infection in hedgehogs, further studies are needed to evaluate the threat this parasite represents to European wildlife.

A recent study in hamsters showed that infection with the liver fluke Opisthorchis viverrini in diabetic hosts worsens the severity of hepatobiliary disease. However, the effects of diabetes on the worm's phenotype and gene expression pattern remain unknown. This study investigated the impact of diabetes on the global gene expression and development of O. viverrini in diabetic hamsters. Parasitological parameters were assessed, and mRNA sequencing with bioinformatic analysis was performed. The study revealed that worm establishment rates in diabetic hamsters were directly correlated with fasting plasma glucose levels. Interestingly, worms collected from diabetic hosts exhibited stunted growth and reduced egg production. Transcriptomic analysis revealed significant alterations in gene expression, with 4314 and 567 differentially expressed genes at 21- and 35-days post-infection, respectively. Gene ontology enrichment analysis highlighted changes in biological processes related to stress response, metabolism, and cellular organization. Notably, genes associated with parasite virulence, including granulin, tetraspanins, and thioredoxins, showed significant upregulation in diabetic hosts. These findings demonstrate the profound impact of host diabetic status on O. viverrini development and gene expression, providing insights into the complex interplay between host metabolism and parasite biology, including molecular adaptations of O. viverrini in hosts. This study contributes to our understanding of opisthorchiasis in the context of metabolic disorders and may inform future strategies for disease management in diabetic human populations.

A parasitological investigation of Cyprinella venusta and Notropis cf. stramineus sampled in Texas, USA, in the Guadalupe River, revealed the presence of Gyrodactylus crysoleucas Mizelle and Kritsky, 1967 on C. venusta, and Gyrodactylus mediotorus King, Marcogliese, Forest, McLaughlin & Bentzen, 2013 on both fish species. This represents new leuscicid fish hosts and locality records for these two gyrodactylids. Gyrodactylus crysoleucas previously identified from both non-native Californian Notemigonus crysoleucas and from farmed stocks in Minnesota demonstrated intraspecific variability in terms of morphology and genetics as a local adaptation associated with isolation by distance. Results further confirmed G. crysoleucas as alien in the western USA and suggested host-switching involving C. venusta and N. crysoleucas. Conservative morphology and genetics on the part of G. mediotorus from C. venusta and N. cf. stramineus (Guadalupe River) was observed, while higher genetic divergence in the ITS sequences associated with morphological discrepancy was found between the studied G. mediotorus specimens and those of Notropis hudsonius than when considering the parasites of Notropis texanus. The separation of G. mediotorus into geographical subgroups may indicate ongoing speciation linked to the Pleistocene glaciations in North America, and to hydrographic barriers that facilitated separate evolutionary paths leading to speciation. We suggest that deep investigations of Gyrodactylus populations will help to understand the speciation of these parasites and their adaptation to Nearctic fish hosts.

Global changes in climate are contributing to modified Phlebotomine sand fly presence and activity, and the distribution of the pathogens they transmit (e.g., Leishmania and Phlebovirus), and are leading to their possible extension toward northern France. To predict the evolution of these pathogens and control their spread, it is essential to identify and characterize the presence and abundance of potential vectors. However, there are no recent publications describing sand fly species distribution in France. Consequently, we carried out a systematic review to provide distribution and abundance maps over time, along with a simplified dichotomous key for species in France. The review adhered to PRISMA guidelines, resulting in 172 relevant capture reports from 168 studies out of the 2646 documents retrieved, of which 552 were read and 228 analyzed. Seven species were recorded and categorized into three groups based on their abundance: low abundance species, abundant but little-studied species, and abundant vector species. Sand flies are certainly present throughout France but there is a greater diversity of species in the Mediterranean region. Phlebotomus perniciosus and Ph. ariasi are the most abundant and widely distributed species, playing a role as vectors of Leishmania. Sergentomyia minuta, though very abundant, remains under-studied, highlighting the need for further research. Phlebotomus papatasi, Ph. perfiliewi, Ph. sergenti, and Ph. mascittii are present in low numbers and are less documented, limiting understanding of their potential role as vectors. This work provides the necessary basis for comparison of field data generated in the future.

Enterocytozoon bieneusi is a zoonotic pathogen prevalent in mammalian and avian hosts across the globe. Wild small mammals, being abundant worldwide, serve as important sources of zoonotic disease transmission to humans. Here, 227 fecal samples were collected from five rodent and shrew species on 34 pig farms in China to investigate the prevalence and molecular characterization of E. bieneusi. The overall prevalence of E. bieneusi was 17.18% (39/227), with a distribution of 23.53% (32/136) in Rattus tanezumi, 8.62% (5/58) in Rattus norvegicus, and 8.00% (2/25) in Mus musculus. Eight E. bieneusi genotypes were identified, comprising four known genotypes: D (n = 8), EbpC (n = 8), PigEBITS7 (n = 9), and EbpA (n = 2), and four novel genotypes: CHPR1 (n = 7), CHPR2 (n = 1), CHPR3 (n = 2), and CHPR4 (n = 2). This study is the first to report E. bieneusi in rodents from pig farms in Henan, Shaanxi, and Shanxi Provinces in China. The host range of genotype EbpC was expanded with its first detection in M. musculus and R. tanezumi. All identified E. bieneusi genotypes belong to group 1, raising concerns about these sympatric rodents being reservoirs of zoonotic transmission. Moreover, the widespread distribution of genotype EbpC suggests potential cross-species transmission between sympatric rodents and domestic pigs. Our findings highlight the potential role of sympatric rodents in facilitating the spillover of E. bieneusi from pig farms, which could pose a potential public health threat.

This study was conducted to clarify the host specificity and the geographical distribution of Gasterophilus species (Diptera, Oestridae) in the Serengeti ecosystem. A total of 317 larvae were recovered from two common zebras (Equus quagga, formerly Equus burchellii) in Maswa Game Reserve, and 58 larvae were recovered from an African lion (Panthera leo) in the Serengeti National Park. The study emphasizes the rare occurrence of Gasterophilus sp. in lions, shedding light on the broader life cycle and physiological implications for hosts. Genetic analysis of cox2 genes from Gasterophilus species, sourced from a single geographic location, reveals significant genetic distinctions and host specificity. This study reports the first case of G. intestinalis infestation in an African lion in the Serengeti ecosystem, extending its known range from zebras and other equids, and highlighting ecological and veterinary implications. This unusual prey-predator transmission highlights the value of molecular taxonomic tools in clarifying host-parasite dynamics and guiding targeted conservation strategies.

Understanding the distribution patterns of vector populations is crucial for comprehending the dynamics of vector-borne diseases. However, data on vector composition and abundance in areas of forest and wildlife-human interface in Thailand remain limited. This research aimed to investigate the spatio-temporal distribution and species diversity of stomoxyine flies (Diptera: Muscidae) in Salakpra Wildlife Sanctuary, Thailand's first wildlife sanctuary. A longitudinal entomological survey was conducted monthly from May 2022 to April 2023 in four habitats: core forest, grassland forest, a wildlife breeding center, and a local cattle farm. A total of 11,256 stomoxyine flies from four genera were captured. Based on morphological keys, nine species of stomoxyine flies were identified: Stomoxys pullus (29.63%), Stomoxys calcitrans (19.65%), Stomoxys indicus (16.09%), Haematostoma austeni (14.23%), Haematobia irritans exigua (8.22%), Haematobosca sanguinolenta (7.96%), Stomoxys uruma (1.98%), Stomoxys sitiens (1.75%), and Stomoxys bengalensis (0.49%). Heterogeneous variations in abundance across months and habitats were observed, in which abundance increased in the rainy season (June-October), exhibiting bimodal peaks at seasonal transitions. Human-disturbed areas, such as the cattle farm, exhibited the highest density and species diversity of stomoxyine flies. In contrast, areas with minimal human disturbance, like core forest, had low diversity and density but supported unique species, like the abundant Haematostoma austeni, which had minor populations in other types of habitats. The results of this study can be integrated into epidemiological models and lay the groundwork for more comprehensive research on vector-borne diseases at the wildlife-livestock interface to mitigate transmission risks and preserve biodiversity.

This clinical study assessed the efficacy of a topical combination of esafoxolaner, eprinomectin and praziquantel (NexGard^® Combo) in treating cats naturally infected with the eyeworm Thelazia callipaeda (Nematoda, Thelaziidae). On Study Day (SD) 0, sixteen client-owned cats with eyeworm infection were allocated to an untreated control group (G1, 8 cats) or to a NexGard^® Combo treated group (G2, 8 cats) and subjected to ocular examination. Cats in G2 received the treatment as per label recommendations. On SD 7 and 14 (±1), cats were examined for the presence of eyeworms and clinical signs. On SD 14, eyeworms were collected and counted. On SD 7 and 14, all cats in G1 were still infected with eyeworms, while G2 cats were free from eyeworms on SD 7 and 14, demonstrating 100% efficacy (p < 0.0001). All collected eyeworms were morphologically and molecularly confirmed to be T. callipaeda. On SD 0, fifteen out of the sixteen cats (7 in G1 and 8 in G2) displayed inflammatory ocular signs. On SD 7, all eight untreated cats and seven treated cats displayed inflammatory ocular signs. On SD 14, five out of eight G2 treated cats had recovered, while the eight untreated cats still displayed inflammatory ocular signs. The treatment significantly reduced lacrimation and conjunctivitis (p = 0.0001). No adverse reactions occurred. This clinical study provides evidence that NexGard^® Combo is highly safe and effective for the treatment of T. callipaeda infection in cats under field conditions.