Cultivable microbiota of Proteus anguinus from underground habitats and animals accidently washed to the surface in Croatia

Abstract

Proteus anguinus (olm) is an amphibian endemic to underground cave systems of the Dinaric karst of Central Europe, adapted to a life in complete darkness. Recent studies have demonstrated the global decline of amphibians due to poorly understood microbiological diseases, emphasizing just how little is known about the natural microflora of amphibians. Not much is known about the olm’s microbiota in their cave habitats, and nothing is known about the microbiology of animals washed to the surface. This observational study describes the microbiological analysis of the skin, cloaca and oral cavity of six olms collected from their cave habitats, and 16 collected after being washed out by flows from two springs, to learn more about the olm’s normal microbiota and possible changes after contact with the different environmental conditions on the surface. Standard microbiological procedures, MALDI-TOF and Real-Time PCR were used for microbiological species identification. All animals tested negative for Ranavirus, Batrachochytrium dendrobatidis, Batrachochytrium salamandrivorans and Chlamydia spp. The most abundant fungi isolated were Penicillium spp. and Cladosporium spp. The washed out animals showed a higher diversity of bacterial flora than those from cave habitats, with Acinetobacter johnsonii, Aeromonas hydrophila, Bacillus spp. and Janthinobacterium lividum as the most frequently identified isolates.