Skin bacterial microflora of two closely related mountain newts (Salamandridae) – the Yellow-spotted mountain newt Neurergus derjugini and the Kaiser's mountain newt Neurergus kaiseri – in the wild and in a breeding facility highlight new conservation perspectives

Abstract

Microbiome research is important for the identification of factors that are associated with the ex situ care of amphibians, such as potential contagious and lethal pathogens. Nevertheless, it can be also used to establish whether newts can adapt to exposure to new microbial communities, which would be important for the success of future reintroductions into the natural habitat. There is no available information regarding the skin flora naturally occurring in mountain newts of the genus Neurergus, including the Yellow-spotted mountain newt Neurergus derjugini and the Kaiser's mountain newt Neurergus kaiseri. In this study, skin bacterial microbiota of wild adults and individuals of both species from a captive-breeding facility (CBF) were compared. Four bacteria that naturally occur on the skin of wild adult N. derjugini were identified (Staphylococcus aureus, Bacillus subtilis, Bacillus cereus, Escherichia coli). Six bacteria were positively detected on the skin of wild adult N. kaiseri [S. aureus, B. subtilis, B. cereus, E. coli, Rhodococcus equi, Klebsiella (Enterobacter) aerogenes]. Our results indicate that the skin microbiota of F1 offspring (≤ 2 months of age) from the CBF did not correspond exactly to the microbial community identified in wild adult N. derjugini. However, ≥ 75% of the bacteria found in older individuals (≥ 1 year of age) living at the CBF over the long term corresponded to those of their wild counterparts. It would appear that post-metamorphic and adults of both species might be better able to resist and adapt to natural microbiota than larvae.