Recent research on chiropteran parasites suggests a high prevalence and diversity, and extensive spatial distribution of filarial species; however, ecological and phylogenetic studies are still in their infancy. We sampled blood from 78 bat specimens, collected 1181 ectoparasites at summer colonies in Armenia and Georgia, and used nested-PCR targeting the cytochrome c oxidase subunit 1 (cox1) gene to detect and genotype filarial parasites. The overall prevalence of filarial DNA was 17.9% in blood samples from Myotis blythii, Myotis emarginatus, Miniopterus schreibersii, and Rhinolophus ferrumequinum, and 8.5% in ectoparasites, including two mite species (Eyndhovenia euryalis and Spinturnix myoti) and two bat flies (Nycteribia kolenatii and Penicillidia dufouri). The prevalence of microfilarial infection was significantly higher in mite samples (13.8%) than in bat fly samples (4.1%). Bats with ectoparasites positive for filarial DNA had a significantly higher total number of ectoparasites. Phylogenetic analysis placed the 18 sequences obtained into different closely related clades of onchocercid nematodes, with four different species recorded: two belonging to the genus Litomosa and two to a newly observed genus of the family Onchocercidae. Additionally, two new species of these parasites, one Litomosa sp. and one Onchocercid sp., were genetically recognised. As predicted, the diversity of filarial parasites reflects the diversity of bat hosts in the Caucasus. Extending the sampling effort to more Caucasian bat species will likely reveal previously unknown filarial species. Non-lethal and non-invasive sampling of blood and ectoparasites for molecular screening proved effective for gaining insights into parasite diversity and phylogenetic relationships of bat-infecting filarial nematodes.

• Klíčová slova
• Bat blood parasites, Bat flies, Bat mites, Filarioidea, Nematodes, Onchocercidae, Vector-borne parasites, cox1,
• Publikační typ
• časopisecké články MeSH

BACKGROUND: Filarial infections have been understudied in bats. Likewise, little is known about pathogens associated with the reproductive system in chiropterans. While semen quality is critical for reproductive success, semen-borne pathogens may contribute to reproductive failure. METHODS: For the first time we performed electroejaculation and used computer-assisted semen analysis to provide baseline data on semen quality in a parti-coloured bat (Vespertilio murinus). RESULTS: The semen quality values measured in the V. murinus male appeared high (semen concentration = 305.4 × 106/mL; progressive and motile sperm = 46.58 and 60.27%, respectively). As an incidental finding, however, microfilariae were observed in the bat semen examined. At necropsy, eight adult filarial worms, later genetically identified as Litomosa sp., were found in the peritoneal cavity, close to the stomach, of the same particoloured bat male dying as a result of dysmicrobia and haemorrhagic gastroenteritis in a wildlife rescue centre. Histopathology revealed microfilariae in the testicular connective tissue and the epidydimal connective and fat tissues. A PCR assay targeting cytochrome c oxidase subunit 1 confirmed that adult worms from the peritoneal cavity and testicular microfilariae were of the same filarial species. Mildly engorged argasid mite larvae attached to the bat skin proved negative for filarial DNA and the adult filarial worms proved negative for endosymbiont Wolbachia. CONCLUSION: While the standard filarial life cycle pattern involves a vertebrate definitive host and an invertebrate vector, represented by a blood-sucking ectoparasite, our finding suggests that microfilariae of this nematode species may also be semen-borne, with transmission intensity promoted by the polygynous mating system of vespertilionid bats in which an infected male mates with many females during the autumn swarming. Presence of microfilariae may be expected to decrease semen quality and transmission via this route may challenge the success of reproductive events in females after mating. Further investigation will be necessary to better understand the bat-parasite interaction and the life cycle of this filarial worm.

• Klíčová slova
• Chiroptera, Vespertilio murinus, Wolbachia, electroejaculation, filariasis, semen quality parameters, semen-borne pathogens,
• Publikační typ
• časopisecké články MeSH
• kazuistiky MeSH