Microbiota diversity and anti- bacteria isolated from skin during late hibernation.

Symbiotic microorganisms that reside on the host skin serve as the primary defense against pathogens in vertebrates. Specifically, the skin microbiome of bats may play a crucial role in providing resistance against (), the pathogen causing white-nose syndrome. However, the epidermis symbiotic microbiome and its specific role in resisting in highly resistant bats in Asia are still not well understood. In this study, we collected and characterized skin microbiota samples of 19 in China and explored the differences between -positive and negative individuals. We identified inhibitory effects of these bacteria through cultivation methods. Our results revealed that the Simpson diversity index of the skin microbiota for positive individuals was significantly lower than that of negative individuals, and the relative abundance of was significantly higher in positive bats. Regardless of whether individuals were positive or negative for , the relative abundance of potentially antifungal genera in skin microbiota was high. Moreover, we successfully isolated 165 microbes from bat skin and 41 isolates from positive individuals able to inhibit growth compared to only 12 isolates from negative individuals. A total of 10 genera of -inhibiting bacteria were screened, among which the genera , , and were newly discovered as -inhibiting genera. These -inhibiting bacteria metabolized a variety of volatile compounds, including dimethyl trisulfide, dimethyl disulfide, propylene sulfide, 2-undecanone, and 2-nonanone, which were able to completely inhibit growth at low concentrations.IMPORTANCERecently, white-nose syndrome has caused the deaths of millions of hibernating bats, even threatening some with regional extinction. Bats in China with high resistance to can provide a powerful reference for studying the management of white-nose syndrome and understanding the bats against the pathogen's intrinsic mechanisms. This study sheds light on the crucial role of host symbiotic skin microorganisms in resistance to pathogenic fungi and highlights the potential for harnessing natural defense mechanisms for the prevention and treatment of white-nose syndrome. In addition, this may also provide promising candidates for the development of bioinsecticides and fungicides that offer new avenues for addressing fungal diseases in wildlife and agricultural environments.