重庆地区儿童诺如病毒基因型别特点研究

The characterization of norovirus genotypes in children in Chongqing

目的：了解重庆地区儿童诺如病毒（Norovirus,NV）基因型别特点。方法：收集2008年8月至2009年7月全年轮状病毒抗原阴性的急性非细菌性腹泻标本,用real-time RT-PCR方法扩增NV ORF1-ORF2结合区,测序扩增片段后进行比对并分型及构建系统进化树。结果：全年获得806份标本,共检测出251份为NV阳性标本,其中GⅠ组4例,GⅡ组247例。NV以7~10月份为高发月份,以6～12月龄婴儿最多见。已分型的NV GⅡ基因组（108例）以GⅡ.4/2006b占绝对优势,其构成比达62.96%（68/108）,其余次为GⅡ.3占25.93%（28/108）;GⅡ.6占6.48%（7/108）;GⅡ.2占1.85%（2/108）;此外还分别检测出GⅡ.7、GⅡ.12、GⅡ.13各有1例（1/108）。结论：重庆地区NV夏季发病率较高,流行毒株以GⅡ.2006b为主。

Objective： To investigate the characteristics of norovirus genotype of children in Chongqing.Methods： Stool specimens of nonbacterial acute diarrhea with rotavirus antigen-negative were collected from August 2008 to July 2009.Real-time RT-PCR was used to detect the ORF1-ORF2 junction regions of norovirus.The sequencing fragments of RT-PCR products were blasted in GenBank and classified.Phylogenetic trees were constructed by the neighbor-joining method.Results： 251 of 806 stool specimens were detected for the norovirus-positive,of which 4 cases belonged to GⅠ group and 247,GⅡ group.It was most likely to occur in summer（from July to October）and in 6~12 months children.Among the sub-genotypes of GⅡ group（108 cases had been genotyped successfully）,GⅡ.4/2006b was dominant,with a constituent ratio of 62.96%（68/108）,and GⅡ.3 accounted for 25.93%（28/108）;GⅡ.6,6.48%（7/108）;GⅡ.2,1.85%（2/108）.Besides,GⅡ.7,GⅡ.12,and GⅡ.13 were also detected.Conclusion： The prevalence of norovirus is found higher in summer in Chongqing,and GⅡ.2006b is the dominant genotype.