浙江省2005～2007年流行性脑脊髓膜炎病原学监测及分子分型研究

Surveillance on Pathogens and Study of Molecular Subtyping of Meningococcal Meningitis in Zhejiang Province from 2005 to 2007

目的对浙江省2005～2007年流行性脑脊髓膜炎（流脑）病原学监测结果进行分析，了解脑膜炎奈瑟菌（Neisseria Meningitidis，Nm）的菌群分布、变迁、耐药状况及分子分型特征。方法常规方法做表型鉴定，聚合酶链反应（PCR）特异性引物扩增，脉冲场凝胶电泳（PFGE）参考中国疾病预防控制中心（CDC）传染病预防控制所推荐的方法进行；药物敏感试验参考美国临床和实验室标准机构（CLSI-2007）制定的标准进行。结果116株疑似Nm的血清群构成比分别为：A群52．58％，B群15．52％，C群31．90％；从病人分离的49株中，A群占61．23％，C群占32．65％，而B群仅占6．12％。菌株对环丙沙星、奈啶酸、甲氧苄氨嘧啶产生不同程度耐药，但对青霉素、氨苄西林、美罗培南、氯霉素敏感，分离自不同人群的血清群菌株的耐药性有一定差异。PFGE酶切图谱及聚类分析发现，相同血清群的病人和其密切接触者的分离菌株的PFGE酶切图谱相似度达100％，属同一克隆系；A群和C群菌株的PFGE酶切图谱相似度相对较高，亲缘关系较近，分别有一定相关性，各存在一紧密相关的流行克隆群；B群菌株PFGE酶切图谱呈现较高的多态性。结论浙江省Nm流行菌群正在发生变迁，目前仍以A群为主，但C群是近年来新出现的主要致病血清群。分子分型结果也显示，浙江省存在优势克隆群的A群和C群主要流行菌株。青霉素、氨苄西林、美罗培南、氯霉素类仍可作为浙江省治疗流脑的首选药物。鉴于多数人群对C群Nm缺乏免疫力，以及C群流脑的高病死率，应密切关注C群流脑的发生，以防C群流脑的爆发或流行。

Objective To Analyze the Surveillance on Pathogens Zhejiang Province from 2005 to 2007. To know the serogroups distr of Neisseria Meningitidis in ibution, changes, drug-resist- ance and molecular subtyping. Methods Conventionality phenotypical analysis, PCR, PFGE ac- cording to the methods recommended by China CDC; Drug Sensitivity Test according to the Standardization（CLSI-2007） of USA. Results Among 116 suspected Neisseria meningitidis strains identified serogroup A was 52. 58%, serogroup B was 15.52% and serogroup C was 31.90%. Serogroup A,serogroup B and serogroup C were 61.23%,6.12% and 32.65% in strains isolated from patients. The strains were resistant to ciprofloxacin,nalidixic acid and trimethoprim in different levels, but sensitive to penicillin, ampicillin, meropencm and chloromycetin. There were certain difference in Drug-resistance of Neisseria meningitidis in the serogroups isolated from different people. The PFGE patterns of the strains of contacts and patients were consistent while the serogroups of them were identical by mapping. The similarity attached 100%. So they be- longed to the same clone series with correlation. There were higher similarity in the strains of se- rogroup A or C, for The PFGE patterns were consistent, so there were certain correlation. Each of the two serogroups had a close correlative cloned group. While there were high diversities in the strains of serogroup B by PFGE Conclusions Changes happened in meningitidis in Zhejiang Province. mapping. the Neisseria Serogroup A and C were main serogroup. And Serogroup C was the new main serogroup in recnt years. Molecular subtyping analysis showed that each of the two serogroups was spread in Zhe-jiang Province. Drug-resistance test revealed that penicillin, ampicillin,meropencm and chloromy- cetin could be selected preferentially to cure meningococcal meningitis. Different sensitive drugs should be used in different areas. For immune barrier werent established in most population,and the high mortality of high meningococcal meningitis caused by serogroup C the prevention and control of epidemic of serogroup C should be regarded carefully.