厦门地区婴幼儿腹泻诺如病毒的基因分型研究

Detection and genotyping of norovirus in diarrhea infant feces in Xiamen

目的:了解厦门地区婴幼儿腹泻诺如病毒(Norovirus,NV)分子流行病学特征。方法:收集2010年5月-2011年4月全年轮状病毒抗原阴性的急性非细菌性腹泻标本,用实时荧光RT-PCR法扩增NV ORF1-ORF2结合区,测序扩增片段后进行比对、分型及构建系统进化树。结果:全年共获得366份标本,共检测出81份为NV阳性标本,其中GI组5例,GII组76例,NV在厦门地区全年可见散发,但在每年7月和11月有明显的流行高峰,且腹泻感染患儿主要集中在3岁以下患儿,已分型的NV基因组(55例)以GII-4/2006b占绝对优势,其构成比达60.00%(33/55),其余为GII-3占25.45%(14/55),GII-6占5.45%(3/55),GII-2占3.64%(2/55),此外GII-12、GI-4、GI-5各占1.81%(1/55)。结论:厦门地区NV夏秋季发病率较高,GII-4/2006b变异株为优势株,且感染的NV可能存在病毒重组。

Objective：To give a systemic picture of the epidemiology and learn more about molecular characteristics and genotyping of norovirus in children in Xiamen.Methods： Stool specimens of nonbacterial acute diarrhea with rotavirus antigen-negative were collected from May 2010 to April 2011.One step real-time RT-PCR was used for detecting 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： 81 of 366 stool specimens were detected for the norovirus-positive,of which 5 cases belonged to GI group and 76 in GII group.Norovirus was prevalent year round with the peak season occurring in July and November.Norovirus diarrhea was concentrated in children under 3 years old.Among the sub-genotypes of GII group（55 cases had been genotyped successfully）,GII-4/2006b was dominant,with a constituent ratio of 60.00%（33/55）,and GII-3 accounted for 25.45%（14/55）;GII-6,5.45%（3/55）;GII-12,1.81%（1/55）;GII-2,3.64%（2/55）;GI-4,1.81%（1/55） and GI-5,1.81%（1/55）.Conclusion： The peak season of norovirus diarrhea is summer and autumn in Xiamen.GII-4/2006b is the dominant genotype and there maybe many recombinant norovirus spreading in Xiamen.