浙江省2008-2009年三起诺如病毒胃肠炎暴发的病原分子特征分析

目的 分析浙江省3起病毒性胃肠炎暴发疫情的诺如病毒分子特征.方法 收集监测期间病毒性胃肠炎暴发疫情患者的粪便标本,采用荧光定量RT-PCR方法检测诺如病毒,并选择部分阳性标本扩增部分多聚酶区(RdRp)和衣壳蛋白区,同时采用3′RACE(rapidamplification of cDNA 3′ends)扩增诺如病毒基因组3′末端,获得完整的开放读码框架(ORF)2和ORF3序列.结果 3起暴发疫情共检测标本62份,诺如病毒阳性41份,其中诺如病毒Ⅰ(G Ⅰ)基因组阳性27例,Ⅱ基因组(GⅡ)阳性9例,G Ⅰ+GⅡ阳性5例.结果 显示,引起浙江省2008-2009年3起病毒性胃肠炎暴发疫情的诺如病毒具有病毒基因型的多样性,包括G Ⅰ.8、GⅡ.b、GⅠ.2与GⅠ.6重组株、GⅠ.8和GⅡ-b混合感染.结论 诺如病毒是浙江省病毒性腹泻暴发疫情的重要病原体,呈现出病毒基因型的多样性,并在省内首次检测到诺如病毒的重组和混合感染毒株.

Abstract：

Objective To study the molecular characteristic of norovirus in 3 outbreaks of gastroenteritis in Zhejiang province. Methods During January 2008 and December 2009, fecal specimens of patients were collected from 3 outbreaks of acute viral gastroenteritis. Noroviruses were detected by Real-time RT-PCR. Part of the positive samples were randomly selected and detected by RT-PCR. PCR products were sequenced. Sequence analysis was undertaken based on partial sequence of RNA dependent RNA polymerase(RdRp)and capsid protein gene. Some positive samples were amplified by 3' RACE(rapid amplification of cDNA 3' ends), 3200 bp in length. The exact whole ORF2, ORF3 and 3' untranslation regions(UTR)gene of norovims were identified. Results There were in total 3 outbreaks of viral gastroenteritis caused by norovirus being reported. A total of 62 stools were obtained from cases with acute gastroentefitis. Noroviruses were detected in 41 cases including 27 strains of genogroup Ⅰ norovirus and 9 strains of genogroup Ⅱ norovirus, 5 strains of genogroup Ⅰ + Ⅱ norovirus. Four genotypes including G Ⅰ .8, G Ⅱ .b, G Ⅰ .2/0 Ⅰ .6 recombination together with co-infection of G Ⅰ .8 and G Ⅱ .b were detected. Conclusion Norovirus was confirmed as the major cause of outbreaks of viral gastroenteritis in Zhejiang province and multiple genotype of norovirus were identified from the outbreaks. It was the first time to have found a recombinant of G Ⅰ .6 capsid and G Ⅰ .2 polymerase norovims as well as the co-infection of G Ⅰ .8 and G Ⅱ .b norovirus in the same sample.

Molecular characteristics of norovirus in 3 outbreak-episodes of gastroenteritis in Zhejiang from 2008 to 2009

Objective To study the molecular characteristic of norovirus in 3 outbreaks of gastroenteritis in Zhejiang province. Methods During January 2008 and December 2009, fecal specimens of patients were collected from 3 outbreaks of acute viral gastroenteritis. Noroviruses were detected by Real-time RT-PCR. Part of the positive samples were randomly selected and detected by RT-PCR. PCR products were sequenced. Sequence analysis was undertaken based on partial sequence of RNA dependent RNA polymerase(RdRp)and capsid protein gene. Some positive samples were amplified by 3' RACE(rapid amplification of cDNA 3' ends), 3200 bp in length. The exact whole ORF2, ORF3 and 3' untranslation regions(UTR)gene of norovims were identified. Results There were in total 3 outbreaks of viral gastroenteritis caused by norovirus being reported. A total of 62 stools were obtained from cases with acute gastroentefitis. Noroviruses were detected in 41 cases including 27 strains of genogroup Ⅰ norovirus and 9 strains of genogroup Ⅱ norovirus, 5 strains of genogroup Ⅰ + Ⅱ norovirus. Four genotypes including G Ⅰ .8, G Ⅱ .b, G Ⅰ .2/0 Ⅰ .6 recombination together with co-infection of G Ⅰ .8 and G Ⅱ .b were detected. Conclusion Norovirus was confirmed as the major cause of outbreaks of viral gastroenteritis in Zhejiang province and multiple genotype of norovirus were identified from the outbreaks. It was the first time to have found a recombinant of G Ⅰ .6 capsid and G Ⅰ .2 polymerase norovims as well as the co-infection of G Ⅰ .8 and G Ⅱ .b norovirus in the same sample.