Pathology and Molecular diagnosis of Paramyxovirus infection in Boidae and Pythonidae in Thailand

Abstract

Reptilian paramyxovirus (rPMV) is one of the most important viral infection occurring worldwide in reptiles especially in Boidae and Pythonidae snakes. The members of rPMV are Sunshine virus and Ferlavirus. The infected snakes may show clinical signs related with neuro-respiratory disorder. There are many suspected clinical cases that could not specify the causes. So far, there is no information and available diagnostic laboratory to identify these viruses in Thailand. Thirty-five necropsied snakes and 40 oral and cloacal swabs from snakes with history of neuro-respiratory problems were collected for histopathology and molecular study. Microscopically, no remarkable lesions in the other visceral organs were observed except generalized congestion. Histopathologically, most distinguished lesion of the suspected cases was numerous varied sizes of eosinophilic intracytoplasmic inclusion bodies in liver, pancreas, kidney, spleen, lung and brain. Molecular study found 2 from 26 (7.69%) positives products showed specific amplicons with high nucleotide identity with Sunshine virus. Eleven of 26 (42.31%) positive products showed 91-96% homology sequence to reptilian paramyxovirus group. Sunshine virus and other rPMV were successfully identified by using RT-PCR and genetic sequencing. This study is the first report of rPMV infection in Boidae and Pythonidae snakes in Thailand. The other five sequences shared homology in group but not to Sunshine virus. This may refer to new strain of rPMV. However, advance technology such as next-generation sequencing may obligatory for further study.