2005-2016年北京市侵袭性脑膜炎奈瑟菌分子分型特征研究

Molecular characteristics of invasive Neisseria meningitidis isolated in Beijing, 2005–2016

目的了解2005—2016年北京市侵袭性脑膜炎奈瑟菌(Nm)分子分型特征,为完善预防控制措施提供依据。方法通过玻片凝集对经过生化方法鉴定的24株Nm进行血清分群,用荧光聚合酶链式反应对所有菌株和4份核酸阳性标本进行基因分群检测;采用多位点序列分型方法对收集的28份标本Nm序列进行分型分析,同时对porA和fetA基因进行分型分析。结果北京市侵袭性Nm主要为A、B、C血清群,2009年前16份标本全部为A群和C群,2009年后12份标本全部为C群和B群。A群序列型均属于ST-5克隆群,porA P1.20,9仅在ST-7型中检出,fetA均为F3-1;ST-4821克隆群在C群菌株中占绝对优势,ST-4821型porA有P1.12-1,16-8、P1.7-2,14和P1.20,23-7,fetA均为F3-3。B群序列型结构复杂、分散。结论北京市侵袭性Nm优势菌特征为A:P1.20,9,F3-1:ST-5(ST-5克隆群)和C:P.12-1,F3-3:ST-4821(ST-4821克隆群),且有A群明显减少、B群增长趋势。提示侵袭性Nm随时间变迁已经发生改变,需加强其分子流行病学监测,尤其要关注尚无有效疫苗应对的B群菌株。

Objective To understand the molecular characteristics of invasive Neisseria meningitidis strains isolated from patients in Beijing from 2005 to 2016. Methods After biochemical identification, the serogroups of 24 N. meningitidis strains from the patients in Beijing, 2005–2016, were detected with slide agglutination test. Real time fluorescence quantitative PCR was conducted to identify the genogroups of all the N. meningitidis strains and 4 nucleic acid positive samples. Multi locussequence typing（MLST） was done for the sequence typing of the 28 N. meningitidis samples, and porA and fetA typing were conducted too. Results N. meningitidis A, B and C were predominant during the past 12 years. All the 16 samples detected before 2009 were N. meningitidis A and C positive, all the 12 samples detected after 2009 were C and B positive. The sequence type of all N. meningitidis A strains belonged to ST-5 clonal complex, porA P1.20, 9 was only found in ST-7 and the fetA types of all N. meningitidis A strains were F3-1. ST-4821 clonal complex was predominant in N. meningitidis C strains, which had P1.12-1, 16-8, P1.7-2, 14, P1.20, 23-7 and the fetA types of all N. meningitidis C strains were F3-3. The sequence types of N. meningitides B were complex and dispersed. Conclusion The predominant invasive N. meningitidis in Beijing characterizes by A： P1.20, 9, F3-1：ST-5（ST-5 clonal complex） and C：P.12-1, F3-3：ST-4821（ST-4821 clonal complex）. The trend of obvious decrease of N. meningitidis A and increase of N. meningitidis B is observed, suggesting that the predominant invasive N. meningitidis has changed over time. It is necessary to strengthen the molecular epidemiological surveillance for N. meningitidis, especially N. meningitidis B to which no vaccine is available.