Detection and genetic characterization of norovirus in environmental water samples in Thailand.

• Main Authors: Leera Kittigul, Apinya Panjangampatthana, Kannika Pombubpa, Yuthana Taweekate, Supornwit Pungchitton, Pornphan Diraphat, Kanokrat Siripanichgon
• Other Authors: Mahidol University
• Format: Article
• Published: 2018
• Subjects: Medicine
• Online Access: https://repository.li.mahidol.ac.th/handle/123456789/14900

The aim of this study was to detect and characterize noroviruses (NoVs) in environmental water samples. One hundred and fourteen water samples were collected from a river and irrigation canals in central Thailand during 2006-2007. NoVs were detected by RT-nested PCR in 13% of the samples. The river samples (22%) contained NoVs at a higher frequency than the irrigation canal samples (4%). Among the 15 NoV-positive samples, 9 harbored genogroup (G) I, 2 samples with GII, and 4 samples with mixed GI and GII. DNA sequencing of PCR amplicons and phylogenetic analysis of partial capsid gene revealed that 5 samples were of genotype GI-2, 1 sample was GI-6, and 1 sample was a mix of GI-2 and GII-unclassified genotypes. NoVs in water samples quantified using quantitative RT-PCR were in the range of 4.91 x 10(2) -1.26 x 10(3) copies/ml for NoV GI and 3.51 x 10(3) copies/ml for NoV GII. This is the first study demonstrating the presence of NoV variants in water samples collected from a river and the adjacent canals of Thailand.