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目的分析近年湖北省麻疹病毒流行株基因型别以及血凝素蛋白(H)基因特性。方法对2012-2013年麻疹病毒核酸检测阳性的患者标本,直接提取核酸,采用one-step逆转录—聚合酶链反应方法扩增核蛋白(N)和血凝素蛋白(H)基因,测序后进行同源性和进化分析。结果湖北省麻疹病毒流行株主要为H1基因型的H1a亚型,发现一株D8基因亚型。与中国麻疹疫苗株上海191株的N和H基因比较,其核苷酸同源性分别为91.6%~92.4%和94.6%~94.8%。对湖北省H1a亚型麻疹病毒H基因进化分析发现均属lineage 3b,H蛋白序列分析发现第240和第397位氨基酸分别发生Ser→Asn、Pro→Leu的变异。运用贝叶斯中的马尔科夫链的蒙特卡洛方法,估计H1a基因亚型H基因核苷酸的平均碱基替代率为7.619×10-4取代/位点/年,估算其共同祖先大约出现在1980年。结论湖北省2012-2013年麻疹病毒流行株主要H1a基因型,仅1例D8亚型;与中国疫苗株沪191株相比较,两者在基因特性上存在明显差异,需进一步加强对麻疹病毒基因型别和变异程度的监测。
Objective To analyze the genotypes and hemagglutinin (H) gene characteristics of measles virus in Hubei Province in recent years. Methods The samples of patients positive for measles virus nucleic acid detection from 2012 to 2013 were directly extracted and the nucleoprotein (N) and hemagglutinin (H) genes were amplified by one-step reverse transcription-polymerase chain reaction Homology and evolutionary analysis. Results The majority of measles virus strains in Hubei Province were H1 subtype of H1 genotype and a D8 subtype was found. Compared with the N and H genes of 191 Chinese measles vaccine strains in Shanghai, the nucleotide homologies were 91.6% -92.4% and 94.6% -94.8%, respectively. The analysis of H gene of H1a subtype measles virus in Hubei Province showed lineage 3b. H sequence analysis showed that the mutation of Ser → Asn, Pro → Leu occurred at the 240th and 397th amino acids respectively. Using the Monte Carlo method of Bayesian Markov chain, it is estimated that the average base substitution rate of H1a gene subtype H gene nucleotide is 7.619 × 10-4 substitutions / site / year, and its common ancestor is estimated to be about Appeared in 1980. Conclusion The major H1a genotypes of measles virus in 2012-2013 in Hubei Province were only 1 case of D8 subtype. Compared with the Chinese vaccine strain Shanghai 191, there were significant differences in the gene characteristics between the two strains, Type and degree of variation monitoring.