Diversity of species in mustelids with the first molecular characterization of and .

Species of genus have a wide distribution and are reported in Europe, the Americas, and Asia. Currently, the genus includes 14 nominal species, out of which 9 are parasitic in mustelids. Two species are mostly reported in mustelids from Europe, namely and . Up to now, no genetic sequences are deposited in GenBank for any of the two. The aims of this study were to investigate the distribution, prevalence, and diversity of spp. infecting mustelids in Romania and to genetically characterize the species. Mustelids ( = 247) were collected over a period of 7 years from different locations in Romania and the respiratory tract was removed and examined for nematodes. Detected nematodes were morphologically identified and fragments of two genes were sequenced. Sampled mustelids included Eurasian badger, ( = 102), Eurasian otter, ( = 20), beech marten, ( = 36), European pine marten, ( = 5), steppe polecat, ( = 1), European mink, ( = 1), least weasel, ( = 2), European polecat ( = 78), and marbled polecat, ( = 1). Nematodes from Eurasian badgers were morphologically identified as ( = 13, 12.74%) and ( = 3, 2.94%). Nematodes from the beech martens were identified as ( = 6, 16.66%), ( = 1, 2.78%) and spp. ( = 3, 8.33%). Co-infections with two species were detected in one beech marten ( + = 1, 2.77%) and in one European pine marten [ + ( = 1, 20%)]. Two genes of and were partly sequenced for the first time. We report new host-parasite associations for and . However, further studies are needed in order to determine the host-parasite associations and to improve the understanding of the epidemiology of nematodes.