2006–2017年辽宁省脑膜炎奈瑟菌分子分型研究

Study of molecular type of Neisseria meningitidis in Liaoning,2006-2017

目的对2006—2017年辽宁省流行性脑脊髓膜炎(流脑)患者、密切接触者分离的17株脑膜炎奈瑟菌(Nm)进行分析,了解菌群种类及分子分型特征。方法采用多位点序列分型技术,应用Splits Tree软件、e BURST方法进行菌株遗传进化和聚类分析。结果 17株菌株共有11种不同序列型(ST),分属于ST-5、ST-4821、ST-11克隆群和其他无序列群分类(UA)。ST-5complex/subgroupⅢ所占比例最多,占47.06%(8/17),来自A群的患者5株,密切接触者3株,ST-7型为主要优势型别。ST-4821克隆群有ST-4821型和ST-5664型。ST-4821型来自1例2012年的C群患者,ST-5644型来自1例2012年的B群密切接触者。ST-11克隆群仅1株为ST-11型,来自2009年W135群的密切接触者。B群和不可分群6株有6种ST型,呈多样性,不存在优势序列群。其中ST-12994为新发现ST,来自2017年密切接触者。结论辽宁省流脑菌株分子基因型别多样性,存在多个克隆群,ST-5 complex/subgroupⅢ克隆群为A群优势克隆群。初步揭示了辽宁省Nm的遗传进化关系,为流脑疾病控制和预防提供了有力科学依据。

Objective To analyze 17 strains of Neisseria meningitidis isolated from meningococcal meningitis patients and close contacts in Liaoning province from 2006 to 2017, and understand the sequence type and molecular typing characteristics of N. meningitidis. Methods The genetic evolution and clustering analysis of N. meningitidis strains were carried out by using multi locus sequential typing technique with the software Splits Tree and the method of e BURST. Results There were11 different ST types in 17 strains of N. meningitidis, including ST-5 complex/subgroup Ⅲ, ST-4821, ST-11 complex/ET-37 complex and unassigned complex STs. ST-5 complex/subgroup Ⅲ strains accounted for the highest proportion（about 47.06%,8/17）, 5 strains were from patients infected with N. meningitidis A and 3 strains were from close contacts and ST-7 was the main type. The clones of ST-4821 contained ST-4821 and ST-5664. ST-4821 strain was from a patient with N. meningitidis C in 2012, and ST-5644 strain was from a close contact of patients infected with N. meningitidis B in 2012. Only one strain was ST-11, which was from the close contact of patients infected with N. meningitidis W135 in 2009. There were 6 STs in the six serogroup B and non sero-groupable strains. The sequence type was diverse and there was no predominant sequence group.Among them, ST-12994 was the newly discovered ST type, which was from close contact in 2017. Conclusion Multiple clone groups of N. meningitidis strain existed in Liaoning and the ST-5 complex/subgroup Ⅲ was the main clone group in serogroup A. The study results revealed the genetic evolution of N. meningitidis in Liaoning, also provided scientific evidence for the prevention and control of meningococcal meningitis.