Cutaneous microbiota composition of the Italian stream frog (Rana italica)

In human and wildlife populations natural microbiota plays an important role in health maintenance and prevention of emerging infectious diseases. In amphibians, such diseases are intimately associated with declines and extinctions worldwide, and the skin symbiont communities have been suggested as one of the factors driving the different susceptibility of amphibians to diseases. Most attention has been focused on the activity of amphibian cutaneous bacteria against fungal pathogens, whereas the role of skin microbiota against protist parasites of the genus Amphibiocystidium in the class Mesomycetozoea remained unexplored. In this study, we provided the first data on the cutaneous microbiota composition of the Italian stream frog (Rana italica) and evaluated the potential role of the detected bacteria in defence against the cutaneous infection by Amphibiocystidium. For our purposes, we used the Illumina technology, since it allows to detect also unculturable microbes, and compared the skin-associated microbial assemblages of frogs uninfected and infected by Amphibiocystidium, since members of such genus are unculturable and growth inhibition tests in vitro are not possible. We found that members of the genera Pseudomonas, Flavobacterium and Janthinobacterium, known to have antifungal activity in amphibians, might have a role in protection also against cutaneous infectious diseases by Amphibiocystidium.