中国1998～2004年G9型轮状病毒分子流行病学研究

目的研究中国流行的轮状病毒(Rotavirus,RV)G9型毒株的分子流行病学特征。方法在中国9个地区收集5岁以下腹泻患儿粪便标本,应用酶联免疫吸附试验(ELISA)方法检测RV,对阳性标本用逆转录-聚合酶链反应(RT-PCR)分型,选择G9型毒株进行VP7基因全长克隆测序和分子流行病学分析。结果1998~2004年共检测出RV1 268份,其中45份为G9型(3.5%),昆明最多(34/45),其次是兰州(8/45)、长春(2/45)、卢龙(1/45),北京、郑州、杭州、福州、广州未检测到G9型毒株。对35份G9型标本进行P分型鉴定:15份为P8]型,12份为P6]型,5份为P4]型,1份为P8 4]混合型,2份未能分型。中国1998~2000年以P8]G9毒株流行为主,而2001年后以P6]G9毒株为主。22株G9型病毒VP7基因序列比对结果表明,中国流行的G9型毒株彼此同源性高,同属G9第3亚型。结论中国流行的RV G9型株与世界各地的流行株同源性较高,国内传播范围扩大的趋势值得关注。

Molecular Epidemiologicai Research on Rotavirus Serotype G9 Isolated From 9 Regions in China

Objective To study molecular epidemiology of rotavirus serotype G_9 circulated in China.Methods Stool specimens were collected from children under 5 years with acute diarrhea in 9 regions and tested for rotavirus using Dako ELISA kits.Rotavirus positive samples were typed with RT-PCR,and VP_7 gene of serotype G_9 rotavirus strains were sequenced.Results Between 1998 and 2004 a total of 45 G_9 strains were isolated from four of nine regions accounting for 3.6% of all rotavirus isolates.Most of the G_9 strains(34/45) were isolated from Kunming,Southwest China,followed by Lanzhou,Northwest China (8/45),Changchun,Northeast China(2/45) and Lulong,North China(1/45).Among the 45 G_9 strains,35 strains were P-genotyped with P8] G_9(42.9%,n=15),P6] G_9(34.3%,n=12),P4] G_9(14.3%,n=5),two strains were P-nontypeable and one G_9 strain was found with mixed P genotypes(P).Strain P8] G_9 was most common during 1999-2000 and P6] G_9 was prevalent after 2001.A comparison of the VP_7 gene sequence of 22 G_9 strains indicated that 16 Kunming G_9 strains isolated in 1999-2003 shared 97.5%-99.9% homology each other and shared 97.2%-99.0% homology with 4 Lanzhou G_9 strains isolated in 1999-2004,94.9%-95.9% homology with one Lulong G_9 strain isolated in 2003,93.2%-94.4% homology with one Changchun G_9 strain isolated in 2004,and also high homology with G_9 strains(G_9 lineage 3) isolated from worldwide,specifically from Argentina,Thailand,Vietnam,and Taiwan.Conclusion The G_9 rotavirus strains circulated in China clustered together with G_9 strains isolated from distant parts of the world,and widerly spread of G_9 strains throughout the country is noteable.