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目的分析1999～2005年广州地区O1群和O139群霍乱弧菌代表菌株的致病基因型和PFGE型别,确定霍乱菌株的分子流行病学特征和同源性,研究本地霍乱弧菌的分子特性。方法采用多重PCR方法检测霍乱弧菌的4种致病相关基因,采用限制性内切酶Not I,以脉冲场凝胶电泳技术(PFGE)对菌株进行分子分型,采用分型处理软件BioNumerics Version对PFGE图谱做聚类分析。结果本地霍乱弧菌代表株中存在3种致病基因型(A、B、C型),病例分离的霍乱弧菌多为A型基因,而环境分离的霍乱弧菌则多为C型和B型。总共96株霍乱弧菌分为60个不同的PFGE型,带型范围:8 kb-650 kb。相同或相近的PFGE型(相差1～3条带)存在于多次霍乱暴发疫情分离株中、环境分离霍乱与临床株之间、输入病例与本地病例分离霍乱弧菌间,不同的PFGE克隆型(4～6带及以上)的流行病学联系也较远。结论将致病基因分型、PFGE型与流行病学资料结合,揭示了本地霍乱菌株从受污染的珠江水及水产品传递给人并引起霍乱暴发、散发的特征,提示开展霍乱菌株PFGE分子分型监测及加强地区间合作的必要性和急迫性。
Objective To analyze the pathogenic genotypes and PFGE patterns of representative strains of Vibrio cholerae O1 and O139 in Guangzhou from 1999 to 2005. To determine the molecular epidemiological characteristics and homology of V. cholerae strains and to study the molecular characteristics of V. cholerae . Methods Four pathogenicity-related genes of Vibrio cholerae were detected by multiplex PCR. The strains were genotyped by using pulsed-field gel electrophoresis (PFGE) with restriction endonuclease Not I. The genotyping software BioNumerics Version Cluster analysis of PFGE profiles. Results There were three pathogenic genotypes (A, B and C) in the representative strains of Vibrio cholerae. Most of the isolates of Vibrio cholerae were type A genes, while Vibrio cholerae isolated from the environment were mostly C-type and B type. A total of 96 Vibrio cholerae were divided into 60 different PFGE types, with band sizes ranging from 8 kb to 650 kb. The same or similar type of PFGE (difference of 1 to 3 bands) exist in several cholera outbreak isolates, the environment between cholera and clinical isolates, imported cases and local cases isolated between Vibrio cholerae, different PFGE clonotype (4 to 6 with and above) the epidemiological linkages are far. Conclusion The combination of pathogenic genotyping, PFGE genotypes and epidemiological data revealed that the transmission of local cholera strains from polluted Pearl River water and aquatic products to human and caused the outbreak of cholera and sporadic, suggesting that the cholera strain PFGE molecular fraction The necessity and urgency of monitoring and enhancing interregional cooperation.