Parasitology Research最新文献

Medicinal leeches express a broad variety of anticoagulants and other bioactive factors that are involved in the blood feeding process. For most of the anticoagulants, several genes exist that may encode isoforms of the respective proteins, including hirudins and decorsins. Decorsins negatively affect platelet aggregation, whereas hirudins are potent thrombin inhibitors. Both factors belong to the hirudin superfamily that also includes the group of hirudin-like factors, and all hematophagous leeches analyzed so far contain several gene copies that encode representatives of at least two of the three groups of these factors. Members of the hirudin superfamily may contain only one central globular domain, but others may contain two or more copies. Here we describe the molecular identification and partial functional characterization of a broad variety of putative mono-, bi and multimeric hirudins, decorsins and hirudin-like factors in two Asian medicinal leech species, namely Hirudo nipponia and H. tianjinensis. Some of the monomeric hirudins and decorsins have already been described before, but they represent only a small part of the overall diversity. For the first time, putative monomeric and one oligomeric decorsins of H. tianjinensis were expressed as recombinant proteins, functionally characterized and successfully verified as platelet aggregation inhibitors. In addition we have conducted phylogenetic analyses based on genomic and mitochondrial markers and found convincing evidence that H. nipponia and H. tianjinensis together with members of the genus Whitmania form a monophyletic clade that is clearly distinct from clades that are formed either by European members of the genus Hirudo or by members of the genus Hirudinaria.

Water buffalo are ideal for grazing in restored wetlands due to their anatomical and behavioural adaptations. Unlike cattle or sheep, the water buffalo thrive in such habitats, feeding on rushes and reeds while helping maintain open landscapes. However, these moist environments also harbor risks, particularly parasitic infections by liver flukes (Fasciola hepatica) and the recently widespread rumen flukes, which require aquatic snails as intermediate hosts. For the present study faecal samples were taken once a year from 2016 to 2024 and monthly in two 12-month periods (2019/20 and 2022/23) from a water buffalo herd established in 2014 on a southern German farm and examined for fluke eggs with a sedimentation technique. In addition, climate data were obtained from a nearby weather station to analyse the impact of rainfall and sunshine hours on the fluke prevalence. To test whether blood samples can be used to detect infection with F. hepatica, residual quantities of blood samples from disease surveillance were tested for F. hepatica antibodies using a commercially available ELISA test. Copromicroscopical results showed that fluke prevalence rose significantly within a few years, with F. hepatica prevalence being always higher than C. daubneyi prevalence. Co-infections were common and seasonal patterns inconsistent. Fluke prevalence increased with rainfall and sunshine hours. In the herd, older water buffalo were more prone to liver flukes. The ELISA test for fascioliasis failed even though F. hepatica eggs were present in the faeces. The findings of the study highlight that extensively reared water buffalo are at high risk of trematode infection, which spreads rapidly throughout the herd and reaches high prevalence rates. The specific wallowing behaviour of water buffalo and favourable climatic conditions for parasite development may contribute to this development.