Genotypes and molecular characterization of group A rotavirus in domestic sewage in Yantai, 2014-2016

Abstract

Objective To understand the genotype distribution and molecular epidemiological characteristics of the group A rotavirus (RVA) in domestic sewage, and further explore the importance of environmental surveillance in investigating RVA regional circulation. Methods Sewage samples were collected monthly in the city of Yantai from January 2014 to December 2016. After concentration, total RNA was extracted, and RVA VP7 and VP4 coding regions were amplified via RT-PCR. PCR products were purified, cloned and Sanger sequenced. Genotyping and phylogenetic analysis was conducted based on the sequences. Results Thirty-six sewage samples were collected and 86.1% was positive with VP7 and VP4 sequences. A total of 205 VP7 and 239 VP4 nucleotide sequences were obtained, belonging to 4 G genotypes and 6 P genotypes. Among these, G9 (95.6%, 196/205), P[8] (58.6%, 140/239) and P[4] (28.0%, 67/239) were the most common genotypes. Phylogenetic analysis for G9, P[8] and P[4] sequences revealed co-circulation of multiple transmission chains in local population. Conclusions This study describes the genotype distribution and sequence characteristics of local RVA in Shandong province, and the result demonstrate that surveillance on environmental sewage is an effective way in investigating RVA molecular epidemiology. Key words: Rotavirus A; Acute gastroenteritis; Molecular epidemiology; Environmental surveillance