Gastrointestinal Helminths of a European Moose Population in Poland

Elucidating nematode diversity and prevalence in moose across a wide latitudinal gradient using DNA metabarcoding

Parasitic nematodes are ubiquitous and can negatively impact their host by reducing fecundity or increasing mortality, yet the driver of variation in the parasite community across a wildlife host's geographic distribution remains elusive for most species. Based on an extensive collection of fecal samples (n = 264) from GPS marked moose (Alces alces), we used DNA metabarcoding to characterize the individual (sex, age class) and seasonal parasitic nematode community in relation to habitat use and migration behavior in five populations distributed across a wide latitudinal gradient (59.6°N to 70.5°N) in Norway. We detected 21 distinct nematode taxa with the six most common being Ostertagia spp., Nematodirella spp., Trichostongylus spp., T. axei, Elaphostrongylus alces, and an unclassified Strongylida. There was higher prevalence of livestock parasites in areas with larger sheep populations indicating a higher risk of spillover events. The individual level nematode richness was mostly consistent across study areas, while the number and type of nematode taxa detected at each study area varied considerably but did not follow a latitudinal gradient. While migration distance affected nematode beta-diversity across all sites, it had a positive effect on richness at only two of the five study areas suggesting population specific effects. Unexpectedly, nematode richness was higher in winter than summer when very few nematodes were detected. Here we provide the first extensive description of the parasitic nematode community of moose across a wide latitudinal range. Overall, the population-specific impact of migration on parasitism across the distribution range and variation in sympatry with other ruminants suggest local characteristics affect host-parasite relationships.

Morphological and molecular data confirm the occurrence of Paramphistomum leydeni (Trematoda: Paramphistomidae) in ruminants from Southern Brazil

Species belonging to the family Paramphistomidae Fischoeder, 1901, commonly known as "rumen flukes", are a group of parasites frequently related to Brazilian livestock production. They inhabit the digestive tract of ruminants and have recognized pathogenicity during the early stages of infection, which can be responsible for economic losses. These trematodes are often associated with Southern Brazil, a region heavily focused on animal farming, which also makes it ideal for the life cycle of paramphistomes. Despite their aforementioned importance, studies regarding their distribution, molecular taxonomy and biology are still scarce in the country. In the present study, rumen flukes collected from cattle (n = 22) and sheep (n = 3) from 9 batches of ruminants from the cities of Jaguarão, Pelotas and Rio Grande, state of Rio Grande do Sul, Brazil, between May and July 2022, were subjected to morphological and molecular study. The microscopic analysis of histological and manual cuts revealed diagnostical traits compatible with Paramphistomum leydeni Näsmark, 1937, including the presence of tegumental papillae, pharynx of the liorchis type and acetabulum of the leydeni type. Molecular data corroborated the morphological identification, with ITS-2 and cox-1 sequences here obtained presenting 100% and 96.8-99.8% similarity, respectively, to P. leydeni samples previously characterized in different countries from Asia, Europe, and South America. Intensity of infection ranged from 5 to 458 and 1 to3 specimens of P. leydeni in sampled cattle and sheep, respectively. The present study contributes to a better understanding of the taxonomy of the flukes involved in cattle and sheep paramphistomosis in Brazil, suggesting that P. leydeni could be the main paramphistome species found in ruminants in the studied region.

Exchanged communities of abomasal nematodes in cervids with a first report on Mazamastrongylus dagestanica in red deer

Introduction

Among large wild game in Poland, the most numerous cervids are red deer and roe deer. Although these species live free, they should be under veterinary supervision because they can transmit infectious agents and parasites to livestock. The aim of this study was to evaluate the biodiversity of the abomasal nematodes which parasitise cervids and present the visual and dimensional characteristics of their spicules.

Material and Methods

Overall, 2,067 spicules of nematodes derived from nine red deer and five roe deer were measured and microphotographed in order to determine the species. The predominant Spiculopteragia boehmi was additionally confirmed molecularly by PCR. The spicule lengths of the most common species found in both hosts simultaneously were compared.

Results

Fourteen species of abomasal nematode were identified. All examined animals but one were infected. The most prevalent parasites in both host species were S. boehmi and Ostertagia leptospicularis. The alien Ashworthius sidemi was found in both hosts, whereas Haemonchus contortus was identified only in red deer. Mazamastrongylus dagestanica was noted in red deer for the first time. A 262-base-pair nucleotide sequence of S. boehmi was obtained and deposited in GenBank. Significantly longer spicules were found in red deer-derived O. leptospicularis and S. boehmi and shorter structures were seen in A. sidemi.

Conclusion

The widespread exchange of abomasal nematodes between various ruminant species questions the relevance of their division into specialists and generalists.