目的对安徽省2005～2008年从流行性脑脊髓膜炎患者及密切接触者分离的脑膜炎奈瑟菌(Neisseria meningitidis,Nm)进行分子流行病学研究,了解菌株间的遗传背景。方法采用多位点序列分析(Multilocus Sequence Typing,MLST)技术,结合PubMLST数据库相关信息,确定97株Nm的序列型别(Sequence Type,ST)。通过Splits Tree4.0、BURST分析软件处理数据,构建遗传图谱。结果 97株Nm共有25个不同ST,分属于ST-4821、ST-175、ST-198、ST-5、ST-41/44克隆群及11个散在ST。其中以ST-4821克隆群最为显著,含8个ST共75株菌。与ST-4821相比,ST-5798、ST-7277、ST-7278、ST-7279、ST-7280克隆群各有1个基因座改变,ST-6051、ST-5664克隆群各有2个基因座的改变。2006～2008年的各年份,ST-4821在ST-4821克隆群中,ST-4821克隆群在总菌株间,均保持高比重,且相对稳定,分别为占81.82%～88.50%、73.33%～80.00%。结论安徽省Nm菌株存在多个克隆群,但以ST-4821克隆群为主导,该群以ST-4821为核心,且相对稳定。尚未发现新克隆群或某一新ST的优势增长。 Objective To study the molecular epidemiology of Neisseria meningitidis isolated from patients with epidemic cerebrospinal meningitis and close contacts in Anhui Province from 2005 to 2008, and to understand the genetic background among strains. Methods The sequence type (ST) of 97 Nm strains was confirmed by using Multilocus Sequence Typing (MLST) and PubMLST database. Splits Tree4.0, BURST analysis software to process the data to construct the genetic map. Results There were 25 different STs among 97 strains of Nm, belonging to ST-4821, ST-175, ST-198, ST-5 and ST-41/44 clones and 11 scattered ST. Among them, ST-4821 clonal group was the most significant, with 8 ST total 75 strains. Compared with ST-4821, there was one locus alteration in ST-5798, ST-7277, ST-7278, ST-7279 and ST-7280 clones, and two genes in ST-6051 and ST- 5664 clones Seat changes. Among ST-4821 clones of ST-4821 in ST-4821 clones for each year from 2006 to 2008, the ST-4821 clonal population maintained a high specific gravity and was relatively stable among the total strains, accounting for 81.82% to 88.50% and 73.33% 80.00%. Conclusion There are many clonal colonies of Nm strain in Anhui Province, but ST-4821 clonal population is the dominant gene. The population of ST-4821 is relatively stable. No new clonal group or a new growth advantage for a new ST has been found.