北京首例输入性ST-11 complex C群流脑死亡病例流行病学及病原学分析

Epidemiology and etiology of the first imported ST-11 complex serogroup C meningococcal disease death case in Beijing

目的了解北京首例输入性ST-11 complex C群流行性脑脊髓膜炎(流脑)死亡病例流行病学特征及分离的ST-11 complex C群脑膜炎奈瑟菌株病原学特征。方法采集疑似病例的血液标本,进行脑膜炎奈瑟菌的分离培养、细菌学鉴定,确定为脑膜炎奈瑟菌;对分离菌株进行血清学分群、实时荧光定量PCR核酸鉴定,同时对鉴定的菌株进行多位点序列分型(MLST)分析、外膜蛋白PorA、fetA基因检测和体外药物敏感试验。结果经细菌学、血清学和实时荧光定量PCR鉴定,该菌株为脑膜炎奈瑟菌C血清群;porA为P1.5-1,10-8,fetA为F3-6;多位点序列分型分析表明,该菌株基因序列型(ST)为ST-2724,属于ST-11/ET-37克隆系;该菌株对氨苄西林和复方新诺明为中等耐药,对其他10种抗菌药物均敏感。结论该菌株为脑膜炎奈瑟菌C:P1.5-1,10-8:F3-6,序列型是ST-2724,属ST-11/ET-37克隆系,对常用抗菌药物尚未出现耐药现象。这是我国首次分离到的ST-11/ET-37克隆系C群脑膜炎奈瑟菌株,为输入性,提示应加强流脑病原学监测。

Objective To understand the epidemiological and etiological characteristics of the first imported ST - 11 complex serogroup C meningococcal disease case in Beijing. Methods Blood specimen was collected from the suspected death case. Neisseria meningitis isolation, identification and serotyping were conducted with routine test, real-time fluorescent quantitative polymerase chain reaction （PCR） and multi locus sequence typing （MLST）, and outer membrane protein PorA,fetA gene were detected. The drug susceptibility test to 12 antibiotics was conducted too. Results The isolate belonged to N. meningitidis serogroup C. The PorA and fetA allele of this strain were P1.1 - 5, 10 -8 and F3 - 6 respectively. Its sequence type was ST - 2724. The strain was sensitive to 10 antibiotics, but intermediate resistant to ampicillin and trimethoprim-sulfamethoxazole. Conclusion The isolate had a phenotype C： P1.5 -1, 10- 8：F3 -6 and its sequence type was ST- 2724, which belong to ST- 11/ET- 37 clonal complex. No resistances to commonly used antibiotics were detected. This was the first ST- 11/ET- 37 clonal complex serogroup C Neisseria meningitidis strain detected in China.