基于生活污水监测的诺如病毒分子流行病学研究

Norovirus Molecular Epidemiology Based on Environmental Sewage Surveillance

为了解生活污水中诺如病毒（Norovirus,NoV）检出情况、基因型分布和分子流行病学特征,进一步探索环境监测技术用于研究病毒性胃肠炎病原区域性流行的必要性,本研究于2016年1-12月在山东省济南和临沂两地采集生活污水,通过阴离子膜吸附洗脱法对收集到的24份污水样品进行浓缩后,提取核酸,经过逆转录-聚合酶链反应扩增NoV VP1基因片段,经TA克隆后测序,进行分型和系统进化树分析。结果显示,监测地区生活污水标本中GI的检出率为100%,GII为95.8%。共获得412条NoV序列,分别属于6个GI基因型和8个GII基因型,其中GI.6（32.3%,133/412）、GII.3（14.1%,58/412）和GII.17（25.7%,106/412）检出数量最多。GII.17检出序列均属于Kawasaki 308变异株,而前些年大流行的GII.4的检出序列占比仅1.0%,属于Sydney 2012变异株。本研究描述了2016年山东省本地流行的诺如病毒基因型分布和序列特征,证明了可以通过对城市污水进行监测来探索人群中循环的诺如病毒的遗传多样性。

We wished to detect the genotype distribution and molecular epidemiological characteristics of the norovirus（NoV）in domestic sewage.We also wished to explore the environmental surveillance methods needed to study regional epidemics of viral gastroenteritis.Hence,we collected sewage in Jinan and Linyi of Shandong Province,China,from January to December in 2016.Twenty-four sewage samples were concentrated by an anion membrane adsorption-elution method,the viral RNA extracted,and fragments of the NoV VP1 gene amplified by reverse transcription-polymerase chain reaction.After cloning and sequencing of TA,obtained sequences were subjected to genotyping and phylogenetic analysis.The detection rate for NoV GI and GII in sewage samples was 100%.We obtained 412 NoV sequences in total,which belonged to six GI genotypes and eight GII genotypes.GI.6（32.3%,133/142）,GII.3（14.1%,58/412）and GII.17（25.7%,106/412）were the most prevalent.GII.17 sequences belonged to the Kawasaki 308 variant.Only 1.0% of GII.4 sequences,（which have caused pandemics in previous years）were detected,and belonged to the Sydney 2012 variant.This study describes the genotype distribution and sequence characteristics of local NoV in Shandong Province and proves that the genetic diversity of NoV in a population can be explored through monitoring of urban sewage.