Tim Hyndman

This thesis describes the isolation and molecular identification of a novel paramyxovirus found in Australian snakes. The virus is named Sunshine virus after the geographical origin of the first isolate: the Sunshine Coast of Queensland, Australia. For decades, Australian veterinarians have been presented with snakes displaying neurorespiratory signs. The clinical signs, pathological findings and the results of overseas diagnostic testing, have suggested that at least some of these snakes were infected with paramyxoviruses, most likely ferlaviruses. Australian veterinarians provided 463 samples to be screened for the presence of viruses and nine were found from five snakes from two collections. For all isolates, cytopathic effects consisted of extensive syncytial cell formation with minimal cell lysis. Further characterisation was performed on one of these isolates, BHP1-Lung (from a lung homogenate of a black-headed python [BHP], Aspidites melanocephalus with mild respiratory signs and stomatitis). Testing this isolate for haemagglutinating and neuraminidase activity provided equivocal results. The virus could not be found by electron microscopy. Polymerase chain reaction to detect a broad range of paramyxoviruses, reoviruses, adenoviruses and herpesviruses was also non-contributory. Through the use of high-throughput sequencing, BHP1-Lung was identified as a novel paramyxovirus. Phylogenetic analysis of the nucleoprotein (N), matrix (M), fusion (F) and polymerase (L) proteins clustered this virus within the family Paramyxoviridae but outside of both subfamilies. Primers were designed that could detect Sunshine virus which enabled clinical data that is associated with Sunshine virus infection to be described. Clinical signs are typically non-specific (e.g. regurgitation, lethargy, inappetence) and/or can be localised to the neurological and/or respiratory systems. Gross pathology is usually unremarkable. Histopathological findings consist primarily of white matter spongiosis and gliosis of the hindbrain with a mild bronchointerstitial pneumonia.