论文部分内容阅读
目的分析泰安市2006~2008年度分离的B型流感病毒HA1基因序列,探究其基因变异特点及种系进化分布,为流感防治提供技术支持。方法采集监测医院流感样病例鼻、咽拭子标本,分离流感病毒并进行型别鉴定,选取部分B型流感病毒株提取病毒RNA,采用逆转录-聚合酶链反应扩增血凝素基因,扩增产物经纯化后进行血凝素基因HAl区核苷酸序列测定并推导编码的氨基酸序列,然后用DNAsTAR MegAlign序列分析软件进行基因种系进化特性分析。结果 2006/2007年度分离的B型流感病毒均为Victroria系;2007/2008年度以Yamagata系为优势株,也有少量Victroria系活动。与B/Shanghai/361/2002/2和B/Tianjin/144/05比较,Yamagata系泰山分离株HA氨基酸替换数为8~10个,所有毒株均在7~9个相同氨基酸位点发生了相同替换;与疫苗推荐株B/Malaysia/2506/2004比较,Vic-troria系泰山分离株氨基酸替换数为2~3个,所有毒株均在HA2个相同氨基酸位点发生了相同替换。结论 Yama-gata系泰山分离株HA1基因特性已发生改变,从基因水平说明当地Yamagata系流行株抗原发生了变异;Victroria系分离株基因特性虽有所改变,但是否已成为有流行病学意义的变异株,尚有待进一步观察。2006/2007年度流感疫苗对当地B型流感应有一定预防作用,2007/2008年度疫苗对B型流感的预防效果欠佳。
Objective To analyze the HA1 gene sequence of influenza B virus isolated from 2006 to 2008 in Tai’an City and explore its genetic variation and phylogenetic distribution to provide technical support for the prevention and treatment of influenza. Methods Samples of nasal and throat swabs were collected from hospital for surveillance of influenza-like illness. Influenza virus was isolated and identified by typing. A portion of influenza B virus strains were selected for viral RNA extraction, and hemagglutinin gene was amplified by reverse transcription-polymerase chain reaction The amplified product was purified and the HAl region of the hemagglutinin gene was sequenced. The encoded amino acid sequence was deduced. Then the evolutionary characteristics of the germline gene were analyzed by DNAsTAR MegAlign sequence analysis software. Results The influenza B viruses isolated in 2006/2007 were both Victroria strains. The predominant strains were Yamagata strain in 2007/2008. There were also a few Victroria strains. Compared with B / Shanghai / 361/2002/2 and B / Tianjin / 144/05, the number of HA amino acid substitutions in Taishan isolate of Yamagata strain ranged from 8 to 10, and all strains occurred at the same amino acid positions from 7 to 9 Compared with the vaccine recommended strain B / Malaysia / 2506/2004, the number of amino acid substitutions in the Taishan isolate of Vic-troria strain was 2-3, and all the strains were replaced by the same amino acid sequence in HA2. Conclusion The characteristics of HA1 gene of Taishan isolates from Yama-gata strain have been changed. The antigenic variation of strains of Yamagata strain from the local gene level has been revealed. Although the gene characteristics of Victroria isolates have changed, whether they have become epidemiologically significant Mutants, yet to be further observed. The 2006/2007 influenza vaccine has a certain preventive effect on local influenza B, and the preventive effect of the vaccine against influenza B in 2007/2008 is not good.