陕西省ST4821克隆群的B群 脑膜炎奈瑟菌的发现

目的 针对一起流行性脑脊髓膜炎疫情的处理,对患者标本及其接触者进行脑膜炎奈瑟菌检验,了解感染原因、分析密切接触者的脑膜炎奈瑟菌携带情况及菌株的分子流行病学特征。方法 对患者标本和接触者的咽拭子标本同时进行分离培养并提取核酸,PCR检测脑膜炎奈瑟菌;分离菌株和患者血清核酸进行血清分群及多位点序列分型(MLST)分析。结果 患者血清及4份咽拭子标本核酸检测ctrA基因阳性。其中密切接触者中分离到3株脑膜炎奈瑟菌;患者血清标本及分离菌株均为B群脑膜炎奈瑟菌;MLST分型显示患者血清为ST4821序列型、其余3株细菌分别为ST7623、ST4821、ST5586。结论 实验显示一种高致病性的ST4821型脑膜炎奈瑟菌已存在于陕西省健康人群中并引发感染病例致患者死亡,应全面了解本地区脑膜炎奈瑟菌的健康携带和病例状况。

Detection of serogroup B Neisseria meningitides belonging to ST4821 complex in Shaanxi

Objective To understand the etiology of a meningococcal disease case,the carriage of Neisseria meningitides in the patient＇s close contacts and the molecular epidemiology of the strains isolated.Methods PCR was performed to detect N.meningitides and its serogroup in the patient＇s serum and throat swabs were collected from the close contacts for the culture of N.meningitides and the determination of their serogroup.All the strains isolated and the patient＇s serum were analyzed with MLST.Results The ctrA gene was positive in the patients＇ serum and 4 throat swabs.Three strains of N.meningitides were isolated from 15 throat swabs of the close contacts;The N.meningitides detected in the patient＇s serum and isolated from the close contacts belonged to serogroup B.The MLST serotyping indicated that the N.meningitides detected in the patient＇s serum belonged to ST4821 complex,the other 3 strains belonged to ST7623,ST4821 and ST5586 respectively.Conclusion A high pathogenic N.meningitides belonging to lineage ST4821 complex was detected in the healthy population in Shannxi,which had caused infection and death.It is necessary to fully understand the carriage and infection status of N.meningitides in Shaanxi.