江西省季节性A(H1N1)流感病毒的基因特点及耐药性分析

Analysis of gene characteristics and drug resistance to amantadine and neuraminidase inhibitors of seasonal A(H1N1) influenza virus during 2005-2009 in Jiangxi

目的分析江西省2005年-2009年季节性H1N1流感病毒M2以及NA基因的特点,掌握其耐药情况,为流感防控提供参考。方法从江西省流感监测网中随机选择26株季节性A(H1N1)流感病毒,经核酸提取和one-step RTPCR扩增M以及NA基因片段,双向序列测定,采用DNAStar 5.0和Mage 4.0序列分析软件分析M2以及NA基因特征以及耐药性位点。结果除2005年分离的3株病毒和2009年分离的2株病毒的M2基因重要位点未发生变异外,其他21株病毒均发生了S31N的氨基酸替换;2009年的5株分离株均发生H274Y突变外,其他21株病毒NA蛋白催化活性位点和辅助位点均未发生氨基酸替换。结论 2005年分离株均对奥司他韦敏感,部分毒株对金刚烷胺类药物耐药;2006年-2008年的分离株对金刚烷胺类药物耐药,但对奥司他韦敏感;2009年的分离株均对奥司他韦耐药,部分毒株对金刚烷胺类药物也耐药,应加强流感病毒耐药性监测。

Objective To analyze the characteristics of M2 and NA genes of seasonal A（ H1N1） virus in Jiang Xi provience from 2005 to 2009, understand their drug resistance and to provide basis for the prevention and control of influenza.Methods From influenza surveillance network of Jiangxi province,26 strains of seasonal A（ H1N1） influenza virus were randomly selected. After virus RNA extraction,fragments of M and NA genes were amplified by one- step RT- PCR and then bidirectional sequencing were conducted. The gene characteristics and resistance sites of M2 and NA were analyzed with the sequence analyzing software DNAStar 5. 0 and Mage 4. 0. Results The important sites of 3 isolates in 2005 and 2 isolates in2009 didn＇t mutate,but amino acid substituted at site S31 N in M2 gene of other 21 isolates; Except H274 Y mutation on the 5isolates in 2009,all other 21 isolates had no amino acid substitution on catalytic active sites and auxiliary sites of virus NA protein. Conclusion All strains isolated in 2005 were susceptible to oseltamivir,and some of them were resistant to amantadine;All strains isolated from 2006 to 2008 were resistant to amantadine but susceptible to oseltamivir; All strains isolated in 2009 were resistant to oseltamivir,and some of them were resistant to amantadine. Continuous resistance surveillance of influenza virus should be strengthened.