中文摘要：

目的分析广东地区2009年至2011年新型甲型HINl流行性感冒（流感）病毒神经氨酸酶（NA）基因变异及其耐药状况。方法采用时空抽样方法，检测广东地区新型甲型H1N1流感病毒NA基因核苷酸序列；比对NA基因核苷酸序列，比较糖基化位点变异，构建马尔可夫链蒙特卡洛模拟进化树（MCMC进化树）；同时分析2009年至2011年广东地区新型甲型H1N1流感病毒株NA基因对NA抑制剂类药物奥司他韦和扎那米韦的耐药现状；计算50％抑制浓度（IC50），并对两种药物分别进行年份病毒株单因素方差分析（one-wayANOVA）。结果2009年至2011年67株病毒株NA基因出现N44S／K、R257K、1365T、N369K、N386S、1389M和1436V变异，2011年病毒株进化树主要分为两主干；2010年至2011年广东地区和其他地区的病毒株发生N44S变异，增加1个糖基化位点NQS42-44；2010年至2011年广东地区病毒株发生N386S变异，减少1个糖基化位点NFS386-388。广东地区病毒株对奥司他韦和扎那米韦均敏感，但出现3个离散值。结论广东地区新型甲型H1N1流感病毒NA基因变异具有地区特征；糖基化位点变异对于病毒株致病性和抗原性的影响，有待于进一步研究；病毒株对NA抑制剂敏感，但应警惕出现耐药株。

英文摘要：

Objective To reveaI variability of neuraminidase （NA） gene and drug sensitivities of the H1N1pdm influenza viruses isolated from Guangdong during 2009 to 2011. Methods Using time- space sampling, NA gene nucleotide sequences of Guangdong H1N1pdm influenza viruses were sequenced and the mutations were analyzed. The glycosylation domains were predicted and Markov Chain Monte＇Carlo simulation tree was established. Meanwhile, drug sensitivities of oseltamivir and zanamivir against H1N1pdm influenza virus NA genes during 2009 to 2011 were detected. The neuraminidase inhibitors （NAI） susceptibility of influenza virus was expressed as the concentration of NAI required to inhibit the NA enzyme activity by 50% （50% inhibitory concentration, IC50 ） and the two drugs against viruses were analyzed by one-way ANOVA. Results Mutation sites of Guangdong isolate NA genes included N44S/K, R257K, I365T, N369K, N386S, I389M and I436V, and Guangdong isolate NA genes in 2011 were divided into two clades. N44S mutation in NA gene of the viruses occurred during 2010 and 2011 in Guangdong and other regions which raised an increase ofglycosylation domain NQS42-44 , and N386S mutation occurred during 2010 and 2011 in Guangdong which raised a decrease of glycosylation domain NFSa86-388. The Guangdong isolates were sensitive to oseltamivir and zanamivir, while presented with three outliers. Conclusions The Guangdong H1Nlpdm NA genes have the regional molecular signatures. The virulence and antigenicity of the virus are affected by mutations in glycosylation domain, which need further investigation. The viruses are sensitive to NA inhibitors, but it is necessary to pay attention to drug-resistant strains.