Molecular detection of novel herpesviruses and adenoviruses in two species of Australian freshwater turtles

Cutaneous lesions were observed in a wild population of freshwater turtles during routine disease surveillance at Alligator Creek, Townsville, Australia. Previous attempts to identify the causative agent of these lesions were unsuccessful; however, existing evidence suggests viral etiology. To further investigate these events, blood samples and lesion, oral and cloacal swabs collected from 128 freshwater turtles at two locations (Alligator Creek and Ross River) were screened for herpesvirus, adenovirus, poxvirus and papillomavirus by polymerase chain reaction. We detected three novel herpesviruses (chelid herpesvirus 1-3) as well as three adenoviruses (saw-shelled turtle adenovirus 1-3). Phylogenetic analyses showed that the herpesviruses formed a distinct clade with the tumour-associated chelonid alphaherpesvirus 5 (Scutavirus chelonidalpha5) within the subfamily Alphaherpesvirinae. The adenoviruses clustered with members of the genus Testadenovirus. Although the novel herpesviruses and adenoviruses could not be linked to the occurrence of cutaneous lesions, further characterisation will help provide better insights into their clinical, epidemiological and conservation significance.