2013年克拉玛依市手足口病EV71型VP1基因特征分析

Study on the genetic characteristics of VP1 gene of EV71 from HFMD in Karamay in 2013

目的掌握2013年克拉玛依市手足口病EV71 VP1基因特征。方法 real-time PCR方法筛选手足口病患者中EV71阳性病例,RT-PCR方法扩增VP1基因片段,结合已知亚型利用Mega软件分析测序结果。结果 59例样本中由肠道病毒引起53例,阳性率为89.8%,其中EV71 36例（67.9%）、CA16 10例（18.9%）、非EV71非CA16的其他肠道病毒7例（13.2%）。男性、女性中各病原阳性率差异无统计学意义（χ^2=3.1504,P=0.207）。12株测序毒株全部为C4亚型,与C4亚型相比较基因距离为0.031～0.046,部分氨基酸序列存在变异,12例EV71至少可以划分为2个传播链,lineage 2较lineage 1序列差异较大。结论各病原对于不同性别人群侵袭力无差异,2013年克拉玛依市手足口病主要病原为EV71。克拉玛依市EV71全部是C4亚型,属于中国大陆广泛流行的基因亚型;lineage 1为2013年克拉玛依市流行的优势分支,分支内同源性较大。lineage 1将来是否继续成为克拉玛依市流行分支,需要对EV71进行连续性监测。

Objective To investigate the genetic characteristics of VP1 gene of EV71 from patients with hand- foot- mouth disease（ HFMD） in Karamay in 2013. Methods Positive cases of EV71 were screened and collected by real- time polymerase chain reaction（ RT- PCR） and VP1 gene was amplified by RT- PCR. PCR products were sequenced and then analyzed by Mega software on the basis of known subtypes. Results 59 samples were detected and 53 of them were caused by enterovirus,the positive rate was 89. 8%. The number of EV71,CA16 and non- EV71 / CA16 were 36（ 67. 9%）,10（ 18. 9%） and7（ 13. 2%）. The positive rate of pathogene was no statistical significance between male and female（ χ^2= 3. 1504,P = 0. 207）.All 12 strains which had been sequenced were C4 subtype and their genetic distance was 0. 031 to 0. 046 in comparison with C4.There were variations among the amino acid sequences. The 12 strains could be divided into at least 2 transmission chains,and the lineage 1 and lineage 2 were greatly different. Conclusion The invasiveness of all pathogenes was no difference between male and female. The main causative agent of hand- foot- and- mouth disease was EV71 in Kamaray in 2013. All EV71 in Karamay was C4 subtype which belongs to pandemic subtype in Chinese mainland. Lineage 1 was dominant branch with high sequence homology. It was necessary to continually monitor EV71 whether Lineage 1 would still be dominant branch or not in the future.