中国1998-2004年G9型轮状病毒分子流行病学研究

Molecular Epidemiological Research on Rotavirus Serotype G_9 Isolated From 9 Regions in China

目的研究中国流行的轮状病毒（Rotavims，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P[8]型，12份为P[6]型，5份为P[4]型，1份为P[8＋4]混合型，2份未能分型。中国1998～2000年以P[8]G9毒株流行为主，而2001年后以P[6]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RVG9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。

Objective To study molecular epidemiology of rotavirus serotype G9 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 VP7 gene of serotype G9 rotavirus strains were sequenced. Results Between 1998 and 2004 a total of 45 G9 strains were isolated from four of nine regions accounting for 3.6 % of all rotavirus isolates. Most of the G9 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 G9 strains, 35 strains were P-genotyped with P[8] G9（42.9% ,n = 15 ）, P [ 6 ] G9 （34.3 %, n = 12）, P [ 4 ] G9 （ 14.3 %, n = 5）, two strains were P-nontypeable and one G9 strain was found with mixed P genotypes （P[ 8 ＋ 4 ] ）. Strain P[ 8 ] G39 was most common during 1999 - 2000 and P[6] G9 was prevalent after 2001. A comparison of the VP7 gene sequence of 22 G9 strains indicated that 16 Kunming G9 strains isolated in 1999 - 2003 shared 97.5 % - 99.9 % homology each other and shared 97.2% -99.0% homology with 4 Lanzhou G9 strains isolated in 1999- 2004, 94.9 96 - 95.9 % homology with one Lulong G9 strain isolated in 2003,93.2 96 - 94.4 96 homology with one Changchun G9 strain isolated in 2004, and also high homology with G9 strains （G9 lineage 3） isolated from worldwide, specifically from Argentina, Thailand, Vietnam, and Taiwan. Conclusion The G9 rotavirus strains circulated in China clustered together with G9 strains isolated from distant parts of the world, and widerly spread of G9 strains throughout the country is noteable.