Parasitology Research最新文献

Enterocytozoon bieneusi is a common cause of human microsporidiosis and can infect a variety of animal hosts worldwide. In Thailand, previous studies have shown that this parasite is common in domestic animals. However, information on the prevalence and genotypes of this parasite in other synanthropic wildlife, including bats, remains limited. Several pathogens have been previously detected in bats, suggesting that bats may serve as a reservoir for this parasite. In this study, a total of 105 bat guano samples were collected from six different sites throughout Thailand. Of these, 16 from Chonburi (eastern), Ratchaburi (western), and Chiang Rai (northern) provinces tested positive for E. bieneusi, representing an overall prevalence of 15.2%. Based on ITS1 sequence analysis, 12 genotypes were identified, including two known genotypes (D and type IV) frequently detected in humans and ten novel potentially zoonotic genotypes (TBAT01-TBAT10), all belonging to zoonotic group 1. Lyle's flying fox (Pteropus lylei), commonly found in Southeast Asia, was identified as the host in one sample that was also positive for E. bieneusi. Network analysis of E. bieneusi sequences detected in this study and those previously reported in Thailand also revealed intraspecific divergence and recent population expansion, possibly due to adaptive evolution associated with host range expansion. Our data revealed, for the first time, multiple E. bieneusi genotypes of zoonotic significance circulating in Thai bats and demonstrated that bat guano fertilizer may be a vehicle for disease transmission.

This work evaluated if strategic control based on no more than three or four annual treatments is useful to control Rhipicephalus microplus infestations on cattle when it is applied to intensive rotational grazing and silvopastoral systems with high stocking rates in subtropical areas. In the intensive rotational grazing system, three annual treatments with chemical acaricides were applied on cattle in two different schemes: between spring and early summer and from late winter and late spring. Strategic control based on three treatments with chemical acaricides from late winter to late spring plus an additional fourth treatment in summer was tested in the silvopastoral system. In the intensive rotational grazing systems, the control schemes allow to reach a significant reduction in the tick load on cattle considering a time interval from spring to autumn. However, the efficacy levels were not high enough in some specific moments, namely, the tick counts of summer and autumn (there were not significant differences between treated and control groups). The scheme evaluated in the silvopastoral grazing system yielded better results than those tested for the intensive rotational system, because significant differences in tick load between treated and control groups were observed in all post-treatment counts and when the analysis was performed for the whole study period. However, values of efficacy in the count-by-count comparison were disparate, ranging from 64.1 to 99.7. Although the efficacy values obtained in the silvopastoral system were better than those of the rotational grazing systems, the total tick load on treated cattle in autumn was not low enough (mean abundance values 25.14 and 38.14). Ticks were more evenly distributed among hosts in late summer and autumn than in spring or early summer, where few hosts carry most of the ticks. Some management strategies as intensive rotational systems or silvopastoral structures can lead to a more efficient forage use, but they imply greater tick challenge than in extensive grazing systems. In these situations, the schemes of strategic control bases on three or four annual treatments should be complemented with additional tactical treatments in late summer or autumn.

Cryptosporidium spp. are protozoa commonly found in domestic and wild animals. Limited information is available on Cryptosporidium in deer worldwide. In this study, 201 fecal samples were collected from Alpine musk deer on three farms in Gansu Province, China. Detection and subtyping of Cryptosporidium were performed by PCR and sequence analysis of the SSU rRNA and gp60 genes. The prevalence of Cryptosporidium infection in Alpine musk deer was 3.9% (8/201), with infection rates of 1.0% (1/100), 2.8% (1/36), and 9.2% (6/65) in three different farms. All positive samples for Cryptosporidium were from adult deer. Two Cryptosporidium species were identified, including C. parvum (n = 2) and C. xiaoi (n = 6). The C. parvum isolates were subtyped as IIdA15G1, while the C. xiaoi isolates were subtyped as XXIIIa (n = 2) and XXIIIg (n = 4). The IIdA15G1 subtype of C. parvum was found for the first time in deer. These results provide important insights into the identity and human infectious potential of Cryptosporidium in farmed Alpine musk deer.

Cryptosporidium is an important water-borne and food-borne parasite with a high burden of disease. This organism has been shown to contaminate various leafy vegetables; however, studies assessing the presence of Cryptosporidium spp in pre-washed and ready-to-eat vegetables are limited. Routine surveillance in the UK revealed a nationwide exceedance of human cases of Cryptosporidium. Therefore, this study aims to assess the presence of this parasite in pre-washed vegetables from supermarkets in the UK. A total of 36 samples were purchased from four different supermarkets. A nested PCR targeting the SSU rRNA was carried out on 24 samples, 58% were PCR-positive for Cryptosporidium. Sanger sequencing confirmed that, of these sequences, 4/24 (17%) produced significant similarities to Cryptosporidium parvum. This study provides evidence for the presence of C. parvum in pre-washed and ready-to-eat vegetables. Future work to identify the point of contamination is required.

A number of studies have been conducted on monogenean seasonality, though primarily in continental regions with wide annual temperatures ranges. We investigated seasonal changes in the prevalence and intensity of Salsuginus seculus infesting sexually dimorphic western mosquitofish (Gambusia affinis) in New Zealand. This represents the first examination of seasonality for this species globally, and the first seasonal assessment of any monogenean population in New Zealand, a temperate country with a mild oceanic climate. Prevalence and intensity of S. seculus with respect to fish size and sex was also examined. Prevalence of S. seculus changed temporally, peaking in summer, and was strongly positively correlated with algal concentrations. This relationship may be associated with increasing food levels, leading to an increase in fish courting and mating, resulting in high numbers and close physical associations of G. affinis individuals, facilitating transmission of the monogeneans. Thus, biotic factors may be important in determining temporal changes in S. seculus prevalence in New Zealand. Female G. affinis had a significantly higher prevalence and mean intensity of S. seculus than males. Longer fish had a higher mean intensity and prevalence of S. seculus. Female G. affinis likely host disproportionately more monogeneans as they are larger than males. Alternatively, females may have a compromised immune response during reproductive periods. Overall, seasonal change was observed in S. seculus prevalence and intensity under New Zealand's mild climatic conditions, and the larger female G. affinis in this dimorphic species supported a greater prevalence and intensity of infestation than males.

The intricate relationships between parasites and hosts encompass a wide range of levels, from molecular interactions to population dynamics. Parasites influence not only the physiological processes in the host organism, but also the entire ecosystem, affecting mortality of individuals, the number of offspring through parasitic castration, and matter and energy cycles. Understanding the molecular mechanisms that govern host-parasite relationships and their impact on host physiology and environment remains challenging. In this study, we analyzed how infection with Microphallus trematodes affects the metabolome of two Littorina snail species inhabiting different intertidal zone shore levels. We applied non-targeted GC-MS-based metabolomics to analyze biochemical shifts induced by trematode infection in a host organism. We have identified changes in energy, amino acid, sugar, and lipid metabolism. In particular, we observed intensified amino acid catabolism and nitrogenous catabolites (glutamine, urea) production. These changes primarily correlated with infection and interspecies differences of the hosts rather than shore level. The changes detected in the host metabolism indicate that other aspects of life may have been affected, both within the host organism and at a supra-organismal level. Therefore, we explored changes in microbiota composition, deviations in the host molluscs behavior, and acetylcholinesterase activity (ACE, an enzyme involved in neuromuscular transmission) in relation to infection. Infected snails displayed changes in their microbiome composition. Decreased ACE activity in snails was associated with reduced mobility, but whether it is associated with trematode infection remains unclear. The authors suggest a connection between the identified biochemical changes and the deformation of the shell of molluscs, changes in their behavior, and the associated microbiome. The role of parasitic systems formed by microphallid trematodes and Littorina snails in the nitrogen cycle at the ecosystem level is also assumed.

In this study, 858 novel long non-coding RNAs (lncRNAs) were predicted as sensitive and resistant strains of Haemonchus contortus to ivermectin. These lncRNAs underwent bioinformatic analysis. In total, 205 lncRNAs significantly differed using log2 (difference multiplicity) > 1 or log2 (difference multiplicity) <  - 1 and FDR < 0.05 as the threshold for significant difference analysis. We selected five lncRNAs based on significant differences in expression, cis-regulation, and their association with the Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathways. These expressions of lncRNAs, namely MSTRG.12610.1, MSTRG.8169.1, MSTRG.6355.1, MSTRG.980.1, and MSTRG.9045.1, were significantly downregulated. These findings were consistent with the results of transcriptomic sequencing. We further investigated the relative expression of target gene mRNAs and the regulation of mRNA and miRNA, starting with lncRNA cis-regulation of mRNA, and constructed a lncRNA-mRNA-miRNA network regulation. After a series of statistical analyses, we finally screened out UGT8, Unc-116, Fer-related kinase-1, GGPP synthase 1, and sart3, which may be involved in developing drug resistance under the regulation of their corresponding lncRNAs. The findings of this study provide a novel direction for future studies on drug resistance targets.

The species Haemonchus contortus occurs in many regions worldwide, mainly parasitising small ruminants and economically impacting animal production. Climate change is considered a driving force for the risk of diseases caused by helminths and can also affect relationships between parasites and their hosts, with the potential to cause losses in both animal production and biodiversity in general. The aim of this study was to model the potential distribution of H. contortus in South America. We used MaxEnt to perform the analyses and describe the contribution of important bioclimatic variables involved in the species distribution. Our results show that H. contortus colonised most of the areas with habitats that suit the species' environmental requirements and that this parasite presents habitat suitability in a future scenario. Understanding the effects of climate change on the occurrence and distribution of parasite species is essential for monitoring these pathogens, in addition to predicting the areas that tend to present future parasite outbreaks and identify opportunities to mitigate the impacts of the emergence of diseases caused by these organisms.

Schistosomiasis is a neglected tropical disease referring to the infection with blood parasitic trematodes of the genus Schistosoma. It impacts millions of people worldwide, primarily in low-to-middle-income countries. Patients infected with schistosomiasis often exhibit a distinct hematological profile, including anemia, eosinophilia, thrombocytopenia, and coagulopathy. Platelets, essential components of the hemostatic system, play a crucial role in the pathogenesis of schistosomiasis. Schistosomes secrete serine proteases and express ectoenzymes, such as calpain protease, alkaline phosphatase (SmAP), phosphodiesterase (SmNPP5), ATP diphosphohydrolase (SmATPDase1), serine protease Sk1, SmSP2, and Sm22.6, which can interfere with platelet normal functioning. This report provides comprehensive, up-to-date information on platelet abnormalities observed in patients with schistosomiasis, highlighting their importance in the disease progression and complications. It delves into the interactions between platelets and schistosomes, including the impact of platelet dysfunction on hemostasis and immune responses, immune-mediated platelet destruction, and the potential mechanisms by which schistosome tegumental ectoenzymes affect platelets. Furthermore, the report clarifies the relationship between platelet abnormalities and clinical manifestations such as thrombocytopenia, coagulation disorders, and the emergence of portal hypertension and gastrointestinal bleeding. Understanding the complex interplay between platelets and schistosomes is crucial for improving patient management and outcomes in schistosomiasis, particularly for those with platelet alterations. This knowledge contributes to improved diagnostic methods, innovative treatment strategies, and global efforts to control and eliminate schistosomiasis.

Mosquitoes (Diptera: Culicidae) are among the most medically significant insects, with several species acting as vectors for human pathogens. Although there are frequent reports of mosquito-borne diseases in the border island areas of Thailand, comprehensive data on the diversity and DNA barcoding of these mosquito species remain limited. This study investigated mosquito diversity in two main archipelagos in Thailand-the Trat archipelago (comprising Chang Island and Kood Island) and the Ranong archipelago (comprising Chang Island and Phayam Island)-and generated DNA barcode data from the mosquitoes found there. The survey across these islands discovered a total of 41 species, highlighting the presence of several species known to be vectors for human diseases. Thirty-seven mosquito species from the island areas were documented to provide reference DNA barcode sequences for mosquitoes in Thailand's island regions. Two species, Aedes fumidus and Finlaya flavipennis, have been added as new COI sequence records in the database. DNA barcoding was highly effective in classifying almost all species by identifying barcoding gaps, except for Anopheles baimaii and Anopheles dirus, which could not be distinguished. Additionally, the study noted that geographical variations might influence certain mosquito species, such as Anopheles barbirostris A3 and Mansonia dives, causing them to be split into two distinct subgroups. The findings of this study are crucial, as they aid in classifying mosquito species using molecular techniques and expand our knowledge of disease vectors in these biodiverse regions.