Abstract

Mycoplasma agassizii and M. testudineum are recognised as significant pathogens causing upper respiratory tract disease in wild and captive terrestrial tortoises in North America and Europe. The origin of these pathogenic mycoplasmas has not been documented. In 2016, Adelaide Zoo acquired an apparently healthy African spurred tortoise (Centrochelys sulcata) from an unknown private source. The tortoise tested positive by PCR on an ocular-nasal-oral swab to M. agassizii. Surveillance of exotic tortoises at Adelaide and Monarto Zoos identified M. agassizii PCR-positive individuals in groups of leopard tortoises (Stigmochelys pardalis), elongated tortoises (Indotestudo elongata), and Aldabra giant tortoises (Geochelone gigantea). Spur-thighed tortoises (Testudo graeca) and a Hermann’s tortoise (T. hermanni) were PCR negative. All were PCR negative for herpesvirus and adenovirus. Exotic chelonids at four other zoos in Australia were surveyed. The species listed above were mostly positive. Star tortoises (G. elegans) and radiated tortoises (Astrochelys radiata) were also PCR positive. A Chaco tortoise (Chelonoidis chilensis) tested positive for M. testudinis. Bell’s hingeback tortoises (Kinixys belliana), Galapagos tortoises (Ch. nigra), and several exotic freshwater turtle species were negative. This is the first time that M. agassizii has been reported in Australia. It appears to be widespread in the captive Testudinidae in the region. Anecdotally, clinical signs consistent with mycoplasmosis have been seen in exotic tortoises held in zoos in Australia; previous diagnostic testing has been unrewarding. The implications for Australian native chelonians remain to be determined.

Acknowledgments

We thank the staff at Perth Zoo, Melbourne Zoo, Werribee Open Range Zoo, and Taronga Zoo for their contributions to regional surveillance.