2009 年全球暴发2009 甲型H1N1 流行性感冒( 简称流感) 疫情, 上海于2009 年5 月出现第1 例输入型病例。为了解上海地区输入型2009 甲型H1N1 流感病毒的生物学特征, 以上海较早发现的2 例输入型甲型H1N1 流感患者作为研究对象, 分离出A/ Shanghai/ 37T/ 2009 和A/ Shanghai/ 71T/ 2009 病毒, 利用实时定量荧光反转录- 聚合酶链反应( RT- PCR) 鉴定病毒, 通过扫描透射电子显微镜观察、免疫荧光检测、全基因组测序和生物信息软件分析, 对这2 株流感病毒形态、结构、耐药性、基因特点和病毒型别等进行研究。结果显示, 病毒呈现正黏病毒颗粒形态特征; 犬肾( MDCK) 细胞内的病毒能与患者恢复期血清反应。此2 株病毒的全基因核酸序列和氨基酸序列与美国参考株A/ Calif ornia/ 04/ 2009( H1N1) 有较高同源性, 其中第31 位氨基酸残基发生改变。对金刚烷胺耐药, 而对奥司他韦敏感。基于全基因组的系统发育分析, 确认此2 株病毒属2009 甲型H1N1 流感病毒。

A new strain of influenza A virus subtype H1N1 first identified in April 2009 has caused global pandemics . The first confirmed case in Shanghai was in May 2009. In order to study the characteristics of the 2009 influenza A virus subtype H1N1 in Shanghai , the virus stains A/ Shanghai/ 37T/ 2009 and A/ Shanghai/ 71T/ 2009, which were identified by real-ti me reverse transcriptase-polymerase chain reaction ( RT-PCR) , were isolated fromtwo i mported cases . Then , the characteristics of viral structure , drug  esistance , gene andsubtyping of the two viruses were studied by electron microscopy , i mmunofluorescence technique , genome sequencing , and bioinf ormation  oftware analysis . Virus particles from Madin- Darby canine kidney ( MDCK) cell culture showed that it contained numerous enveloped and highly pleomorphic orthomyxovirus  articles with a diameter ranging from60 nmto 80 nmand surrounded by a fringe of welldefined surface projection . The genome nucleotide sequence and amino acid  equence were then compared . The results showed that the two virus strains and the reference strain A/ Calif ornia/ 04/ 2009( H1N1) were highly homologous . Amantadine resistance occurred at residue 31 ( Asn) in M2 protein, while in the neuraminidase protein domain, it was sensitive to oseltamivir . Phylogenetic analysis showedthat thetwo strains were highly genetically si milar to those previously reported on the 2009 influenza A virus subtype H1N1 strains , suggesting the same origins f or the two Shanghai strains and 2009influenza A virus subtype H1N1 strains .