感染性腹泻疫情中诺如病毒的分子流行病学分析

Molecular characteristics of noroviruses causing outbreaks of acute gastroenteritis in Huzhou

目的 研究感染性腹泻疫情中诺如病毒的分子流行病学特点.方法 对2008-2010年湖州地区的感染性腹泻疫情标本共119份进行诺如病毒核酸检测,并选取部分阳性扩增产物经序列测定分析诺如病毒的基因型.结果 119份感染性腹泻标本荧光定量PCR检测阳性50份,其中GⅠ型9份,GⅡ型35份,GⅠ和GⅡ混合感染6份.对12份PCR扩增阳性产物进行序列分析显示：5株GⅠ型诺如病毒毒株分属于GⅠ/2和GⅠ/3两种基因型；7株GⅡ型诺如病毒毒株中除1株属于新基因型GⅡb外,其余6株均属于GⅡ/4基因型.结论 诺如病毒是引起湖州地区感染性腹泻疫情最重要的病原菌之一,且湖州地区的诺如病毒存在很高的遗传多样性,同时也存在基因型别的差异.

Objective To study the molecular characteristics of Noroviruses causing outbreaks of acute gastroenteritis in Huzhou.Methods From 2008 to 2010,total 119 fecal specimens collected from outbreaks of acute gastroenteritis were tcsted for Norovirus. Partial sequence of RNA dependent RNA polymerase（RdRp） of the positive samples were amplified by RT-PCR,then the PCR production were purified,sequenced and put into phylogenetic analysis. Results 50 of 119 specimens were positive for Norovirus by real-time RT-PCR.Out of those 50 Norovirus positive specimens,9 were Norovirus Genogroup Ⅰ （GI） positive,35 were Norovirus Genogroup Ⅱ （GⅡ）positive,6 was both Norovirus GⅠ and GⅡ positive.12 PCR products for RdRp were selected for further studies on sequencing.Phylogenetic analysis revealed that the 5 GⅠ norovirus isolates were belonged to genotype GⅠ/2 and GⅠ/3.Of the 7 GⅡ norovirus isolates,6 were belonged to genotype GⅡ/4,1 was belonged to genotype GⅡb.Conclusion Norovirus is a major cause of outbreaks of acute gastroenteritis in Huzhou and the epidemic strains of norovirus isolated from Huzhou had a high degree of genetic diversity.