First detection and phylogenetic analysis of Trypanosoma species in European wolves and bears: discovery of novel haplotypes.

Wild carnivores may be important sources of emerging zoonotic pathogens worldwide, however, specific data concerning their presence in large carnivores are limited. The genus Trypanosoma (protozoan parasites) comprises numerous species adapted to all classes of vertebrates. This genus includes highly pathogenic species, such as T. brucei ssp., T. congolense or T. vivax. The aim of this study was to expand on the ecological or zoonotic significance of detecting Trypanosoma in large carnivores. Samples from free-living carnivores (n = 26) were collected. The diversity and occurrence of Trypanosoma species among wildlife in Europe were investigated through the analysis of 18S rRNA gene sequences. The phylogenetic analysis showed three new haplotypes of the 18S rRNA gene of Trypanosoma sp. isolated from two grey wolves (Canis lupus) and two brown bears (Ursus arctos). To the best of our knowledge, this this study represents the first detection of trypanosomes in large carnivores in Europe. The detection of Trypanosoma sp. was achieved through nested- PCR amplification. Furthermore, the identification of new haplotypes of these protozoan highlights variability within Trypanosoma sp., which could lead to the emergence of new, potentially more virulent variants of these parasites in wild animal populations, posing a potential threat to their health. Moreover, these findings underscore the need for further research to comprehensively understand the diversity, distribution, and potential impact of Trypanosoma species on the populations of large carnivores.