肠道病毒71型中国分离株基因组3区的分析

Nucleotides sequence analysis of EV71 Chinese strain SHZH98 3C Segment

目的测定我国分离的肠道病毒71型(EV71)SHZH98株3C基因的核苷酸序列,进行遗传进化途径的分析。方法 用逆转录聚合酶链反应(RT-PCR)方法扩增我国分离的EV71-SHZH98株3C基因cDNA,测定PCR产物的核苷酸序列。结果SHZH98株3C基因为549 bp,和已发表的肠道病毒71型3C基因序列比较,SHZH98株与MS株同源性为78.7％,与BrCr株的同源性为76.7％,与台湾分离株POLY、NCKU、TW2086、TW2272株的同源性分别为74.0％、73.8％、71.9％、69.8％。由其核苷酸序列推导的氨基酸序列同源性比较显示与MS的同源性为93.45％,与BrCr、POLY、NCKU、TW2086、TW2272株的同源性分别为89.1％、90.7％、90.2％、84.2％、82.5％。遗传进化分析显示SHZH98株3C片段在亲缘关系上与Coxsackievirus A16 G-10株及欧美分离株MS、BrCr株较密切,而与台湾分离株相差较远。结论推测EV71病毒中国分离株非结构蛋白的进化途径可能与台湾流行株不同。

Objective To study the EV71 Chinese strain SHZH98 and analyze its genetic evolution using 3c gene as index. Methods The 3C gene cDNA of EV71 Chinese strain SHZH98 was amplified by PCR, the PCR product was sequenced. Results The EV71 Chinese mainland strain SHZH98 3C segment was 549 bps in length. Comparison of nucleotide sequences from other entreroviruses which have been published, revealed a higher homology to strain MS, 78.7% at nucleotide level and 93.45% at deduced aminoacid level. The homology to strain BrCr was 76.7% at nucleotide level and 89.1 % at deduced aminoacid level. Taiwan strains POLY,NCKU, TW2086,TW2272 shared a lower homology with Chinese mainland strain SHZH98, 74.0% , 73.8% ,71.9% , 69.8% at nucleotide level and 90.7%,90.2%,84.2%,82.5% at deduced aminoacid level. The genetic progress analysis revealed that EV71 Chinese mainland strain SHZH98 3C segment shares more homology with Europeon & American strains than Taiwan strains. Conclusion The non-structrual protein of EV71 Chinese strains may have different evolutionary process from Taiwan strains.