Molecular detection and genetic characterization of Salivirus in environmental water in Thailand

Salivirus (SalV), also known as klassevirus, is a newly discovered member of the Picornaviridae family, which has been proposed to be a potential causative agent of acute gastroenteritis. This study aimed to provide further insight into the currently limited epidemiological data of SalV in environmental water in Thailand, which could be a potential source of human infection. A total of 95 water samples were collected from six locations in Chiang Mai province, northern Thailand, between November 2016 and February 2018. The molecular screening for SalV was performed by the nested polymerase chain reaction. The SalV genotypes were then determined through nucleotide sequencing and phylogenetic analysis. SalV was detected in 31 out of the 95 (32.6%) water samples and all belonged to the A1 genotype, based on phylogenetic analysis of the 5'UTR and 3D regions. The SalV-A1 strains detected in the environmental water were closely related to the SalV-A1 detected in a patient with diarrhoea in the same geographical area, based on the nucleotide sequence identities of the 5'UTR and 3D regions ranging from 91 to 99% and 96-99%, respectively. This study reports the prevalence of SalV-A1 contamination in environmental water in Chiang Mai, Thailand.