目的  了解宁波地区肠道病毒71型（enterovirus 71，EV71）流行株VP1基因特征。方法   采集手足口病患者的样本进行病毒分离和鉴定，用逆转录-聚合酶链反应对EV71流行株VP1进行扩增和测序。对流行株VP1进行进化分析，并将流行株VP1与各基因型代表株进行序列比对。同时测定EV71 流行株的半数组织培养感染量（median tissue culture infective dose，TCID50）。结果  2008—2009年，宁波地区分离出23株病毒，鉴定后其中6株为EV71。EV71 流行株VP1进化分析显示，6株EV71流行株与C4亚型代表株聚于同一分支，流行株VP1的核苷酸和氨基酸序列与C4亚型代表株的同源性最高，分别为92.0%～93.1%和98.9%～99.3%。6株EV71流行株的TCID50为101.16～103.33 TCID50/ml。 结论  2008—2009年宁波地区EV71流行株属于C4亚型。

Objective  To investigate the genetic characterization of the VP1 gene of enterovirus 71 (EV71) in Ningbo.  Methods  The clinical samples were collected from the patients with hand, foot and mouth disease, and EV71 was isolated and identified. The VP1 gene of EV71 isolates was amplified by RT-PCR and sequenced. The adaptive evolution of the VP1 gene of EV71 isolates was analyzed, and the VP1 gene sequences of EV71 isolates were compared with each genotype representative strains. Meanwhile, The TCID50 of isolates was determined. Results  Out of twenty-three isolates, six EV71 strains were identified during 2008-2009. The VP1 gene evolution analysis showed that isolates in Ningbo were clustered with subgenotype C4 representative strain. The VP1 gene of six isolates shared the highest homology with subgenotype C4 both at nucleotide level(92.3%-93.1%) and amino acid level (98.9%-99.3%).  The TCID50 of six EV71 isolates ranged from 101.16 to 103.33 TCID50/ml. Conclusion  EV71 isolates in Ningbo belong to subgenotype C4.