Yeasts in amphibians are common: isolation and the first molecular characterization from Thailand

Abstract

A survey of the presence of yeasts in frogs and toads in Thailand was conducted using standard mycological examination techniques. The results, which were confirmed with molecular techniques, revealed the presence of five yeast species – Cryptococcus liquefaciens, C. heveanensis, Pseudozyma hubeiensis, Rhodotorula mucilaginosa and R. minuta – in the bile of these amphibians. Although previous works have isolated yeasts from amphibian gastrointestinal tracts and skin, it is questionable whether these yeasts were acquired by ingestion or were commensals on adult individuals. Frog farms, an urban area and protected natural areas were surveyed and all tested positive for yeasts, which shows their ubiquity in both wild and farm-reared frogs. Additionally, the finding of yeasts in five different species of frogs and toads shows that there is a wide spectrum of hosts in this vertebrate group. Our results thus suggest that yeasts are likely to be widespread among amphibians in different habitat types and in a wide range of host species.