DAO prepress abstract  -  DOI: https://doi.org/10.3354/dao03172

Serological survey of Australian native reptiles for exposure to ranavirus

E. Ariel*, E. Elliott, J. I. Meddings, J. Miller, M. B. Santos, L. Owens

*Email: ellen.ariel@jcu.edu.au

ABSTRACT: Ranaviruses have been isolated from many ectothermic vertebrates and serological surveys of both amphibians and reptiles have shown the presence of ranaviral antibodies in a proportion of these populations. An enzyme-linked immunosorbent assay (ELISA) was developed to measure serum antibodies against ranavirus in Australian reptiles. The ELISA was validated with serum from challenge trials with Bohle iridovirus (BIV) in six reptilian species. A preliminary sero-survey of northern Queensland riparian reptile fauna (Emydura macquarii krefftii, Crocodylus johnstoni, Boiga irregularis, Dendrelaphis puntulatus, Tropidonophis marii, Morelia spilotes, Liasis childreni, Liasis fuscus) revealed evidence of past exposure to Bohle iridoviral antigens in part of the population at several locations sampled. Furthermore, in Krefft’s river tortoises Emydura macquarii krefftii and freshwater crocodiles Crocodylus johnstoni, a statistically significant trend (F(4,12) = 7.89; P = 0.0023 and F(1,3) = 72; P = 0.0034, respectively) was apparent for larger reptiles to be more likely to have BIV-reactive sera than the smaller individuals. The use of adult tortoise populations as sentinels can assist in monitoring the presence of BIV in northern Australian freshwater streams, and thereby the potential dangers to native fauna from this agent.