一起旅游团中急性胃肠炎的暴发与GII. 17型诺如病毒相关

A GII. 17 Norovirus-associated Acute Gastroenteritis Outbreak in a Tourist Group in Inner Mongolia,China

为了解2016年夏季一起发生在某赴内蒙古旅游团游客中的急性胃肠炎暴发流行的病毒病原。分别采集此次胃肠炎暴发流行中两名患病游客腹泻症状发生后第3天、5天和7天的粪便标本,提取核酸后首先用荧光定量PCR扩增诺如病毒核酸进行检测,阳性标本分别用RT-PCR扩增病毒VP1基因和RdRp区域基因,通过基因测序和序列比对进行基因分型,构建进化树确定进化同源性。通过荧光定量PCR法检测到两名患者的粪便标本均为诺如病毒阳性,提示此次胃肠炎暴发流行的病原为诺如病毒,进一步的RT-PCR扩增病毒基因分析显示检测到的诺如病毒为GII.P17-GII.G17型;构建系统进化树分析显示本次与2014~2015年度广州、中国香港、中国台湾和日本等地的病毒亲缘关系更为接近;氨基酸序列分析显示该基因型与2014年以来流行的毒株同源性较近,与2014年之前流行的毒株相比变异较大,氨基酸变异主要出现在主要衣壳蛋白的P结构域。提示GII.P17-GII.G17型诺如病毒也是引起内蒙地区急性胃肠炎暴发流行的病毒病原。

Noroviruses are the leading cause of outbreaks of acute non-bacterial gastroenteritis in industrialized and developing countries.In August 2016,an outbreak of acute gastroenteritis（AG）were occurred in a tourist group visiting Inner Mongolia,China.We determined whether this outbreak was associated with noroviruses.Fecal samples were collected from two of the AG patients and tested for norovirus by realtime reverse transcription polymerase chain reaction（RT-PCR）.Then,the capsid gene and RdRp gene of the norovirus were amplified by conventional RT-PCR for genotyping.Phylogenetic analyses identified that the causative pathogen of this AG outbreak to have a GII.P17-GII.G17 norovirus genotype and closely related to the virus wide spread in Guangzhou,Hong Kong of China,Taiwan of China,Japan,and other regions in 2014-2015.The alignment of the deduced amino-acid sequence showed high homology with the amino-acid sequence between the GII.17 norovirus of this outbreak and other GII.17 norovirus variant identified since 2014.Comparison of the GII.17 norovirus with that of the new variant showed that the aminoacid mutation of the VP1 occurred mainly in the P domain near or at epitopes and HBGA binding site.