Prevalence of Ranavirus, Batrachochytrium dendrobatidis, B. salamandrivorans, and Ophidiomyces ophiodiicola in Amphibians and Reptiles of North Carolina, USA

The viral pathogen Ranavirus (Rv) and the fungal pathogens Batrachochytrium dendrobatidis (Bd), B. salamandrivorans (Bsal), and Ophidiomyces ophiodiicola (Oo) infect amphibians and reptiles. In recent years, there has been increased interest in reporting the occurrences of these pathogens. North Carolina, USA has a rich diversity of amphibians and reptiles, and is notably the most species-rich U.S. state in salamanders. We assessed prevalence of Rv, Bd, Bsal, and Oo in a broad taxonomic and geographic representation of amphibians and reptiles in North Carolina. Non-lethal skin swabs were taken using standardized methods from 718 amphibians and 254 reptiles, most of which were wild caught across North Carolina, with some captive individuals from living collections at the North Carolina Museum of Natural Sciences and North Carolina State University Veterinary College. The presence and quantity of Rv, Bd, Bsal, or Oo DNA in the swabs was determined by quantitative polymerase chain reaction (qPCR). Rv was found in 29% of the amphibians and reptiles that were tested, Bd was found in 14% of the frogs and salamanders tested, and Oo was found in 10% of the snakes tested. Presence of Bd was positively associated with presence of Rv in frogs but not in salamanders. Rv, Bd, Bsal, and Oo were found in a wide variety of species and across the state. As none of the individuals sampled were apparently sick or coming from populations with recent mass die-off or mortality events, this research suggests that these three pathogens are probably endemic to North Carolina and found naturally in wild populations. Bsal was not found in any samples, consistent with the finding that this pathogen has not yet been detected in the wild anywhere else in the USA. As this pathogen is associated with wild salamander die-offs in Europe, its introduction into salamander-rich North Carolina could be catastrophic. Hence efforts to continue to monitor for Bsal and prevent its introduction into the USA remain very important.