A Culture-Based ID of Micromycetes on the Wing Membranes of Greater Mouse-Eared Bats (Myotis myotis) from the “Nietoperek” Site (Poland)

SIMPLE SUMMARY: This study reports the colonization by fungi of the wing membranes of the female greater mouse-eared bat (Myotis myotis) during spring emergence from the “Nietoperek” underground hibernation site. Overall, we isolated 17 different fungal species and the most commonly isolated was Penicillium chrysogenum—the cosmopolitan species. Some fungal species may be pathogens of mammals, including bats. However, taking into account habitat preferences and the life cycle of bats, it can be assumed that some fungi were accidentally obtained from the surface of vegetation during early spring activity. Therefore, in the near future, we want to study the mycobiota of other bat species because they could be pathogens or part of the normal microbiome. ABSTRACT: Bats play important functions in ecosystems and many of them are threatened with extinction. Thus, the monitoring of the health status and prevention of diseases seem to be important aspects of welfare and conservation of these mammals. The main goal of the study was the identification of culturable fungal species colonizing the wing membranes of female greater mouse-eared bat (Myotis myotis) during spring emergence from the “Nietoperek” underground hibernation site by the use of genetic and phenotypic analyses. The study site is situated in Western Poland (52°25′ N, 15°32′ E) and is ranked within the top 10 largest hibernation sites in the European Union. The number of hibernating bats in the winter exceeds 39,000 individuals of 12 species, with M. myotis being the most common one. The wing membranes of M. myotis were sampled using sterile swabs wetted in physiological saline (0.85% NaCl). Potato dextrose agar (PDA) plates were incubated in the dark at 8, 24 and 36 ± 1 °C for 3 up to 42 days. All fungi isolated from the surface of wing membranes were assigned to 17 distinct fungal isolates belonging to 17 fungal species. Penicillium chrysogenum was the most frequently isolated species. Some of these fungal species might have a pathogenic potential for bats and other mammals. However, taking into account habitat preferences and the life cycle of bats, it can be assumed that some fungi were accidentally obtained from the surface of vegetation during early spring activity. Moreover, Pseudogymnoascus destructans (Pd)—the causative agent of the White Nose Syndrome (WNS)—was not found during testing, despite it was found very often in M. myotis during previous studies in this same location.