EXHAUSTIVE GENETIC ANALYSIS FOR NOROVIRUS GII ACCUMULATED IN CULTURED OYSTES BY USING PYROSEQUENCING

Abstract

 Genotypes of Norovirus (NoV) genogroup II accumulated in cultured oysters were identified by using pyrosequensing. Application of pyrosequencing, instead of direct or cloning sequencing methods, could detect relatively minor genotypes, which existed at an ratio of several percentage per oyster. GII.4 Sydney 2012 variant was detected at quite high ratio of 85-100% from all oyster samples tested and GII.6 was detected at 10% and 15% from some samples. Comparing with epidemic situation, it was indicated that dominant NoV genotypes/variants in oysters were derived from patients in the watershed after last January.