论文部分内容阅读
目的分析2009年珠海市手足口病(HFMD)患者中,肠道病毒71型(HEV71)的分子流行病学特征。方法2009年1—10月采集珠海市各医院就诊的HFMD患者的粪便标本558份,经HEV71通用引物扩增分析,确定为HEV71阳性158份。选取其中HEV71阳性标本24份用RT-PCR扩增衣壳蛋白vp1全长基因,核苷酸序列测定并分析病毒遗传学特征。结果珠海市24例HEV71的vp1基因核苷酸序列的测定结果显示,所有核苷酸序列长度都是891bp,编码297个氨基酸。该24株HEV71全部属于C4基因亚型C4b进化分支,与C4基因型相比较核苷酸同源性在95.4%～98.9%之间,氨基酸同源性在99.3%～99.7%之间,与2008—2009年中国流行的HEV71同源性极高;但24株HEV71在vp1区的核苷酸和氨基酸同源性分别为95.2%～100.0%和99.0%～100.0%,在核苷酸和氨基酸水平上存在一定差异;24例HEV71可划分为7条传播链,75%(18/24)流行株分布在其中的2条传播链,且这2条主要传播链只由珠海市HEV71分离株构成。结论2009年珠海市流行的HEV71属于C4基因亚型C4b进化分支,与中国2008—2009年流行的HEV71在基因亲缘关系和流行时间关系上都很接近,但珠海市HEV71流行株的基因特征存在其特殊性。
Objective To analyze the molecular epidemiological characteristics of enterovirus 71 (HEV71) in Zhuhai city of hand-foot-mouth disease (HFMD) in 2009. Methods From January to October, 2009, 558 stool samples of HFMD patients from Zhuhai hospitals were collected and amplified by HEV71 universal primers. The positive samples were identified as 158 positive for HEV71. The full-length gene of capsid protein vp1 was amplified by RT-PCR from 24 HEV71 positive samples. The nucleotide sequence was determined and the viral genetic characteristics were analyzed. Results The nucleotide sequence of vp1 gene of 24 HEV71 strains in Zhuhai City showed that all nucleotide sequences were 891 bp in length and encoded 297 amino acids. All 24 strains of HEV71 belonged to the C4b evolutionary branch of C4 gene, with nucleotide identities of 95.4% ~ 98.9% and amino acid homologies of 99.3% ~ 99.7% with those of C4 genotype. The homology of HEV71 in China was extremely high in 2009; however, the nucleotide and amino acid homology of 24 HEV71 in the region of vp1 was 95.2% -100.0% and 99.0% -100.0%, respectively. At the nucleotide and amino acid levels 24 cases of HEV71 could be divided into seven transmission lines, 75% (18/24) of the epidemic strains were distributed in two of the transmission chain, and the two major transmission chain only by Zhuhai HEV71 isolates constitute. Conclusion Zhuhai epidemic of HEV71 belongs to the evolutionary branch of C4 subtype C4b in 2009, which is close to the epidemiological relationship between HEV71 and epidemic time in China from 2008 to 2009. However, the genetic characteristics of HEV71 in Zhuhai exist Particularity.