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目的 了解广州市水产品监测中霍乱弧菌分离株的毒力特征,对其菌株进行同源性分析,研究其分子特征及流行病学意义。方法 2 0 0 4年6月采集广州市3家较大的水产品交易市场的海、水产品以及广州以往水型霍乱流行沿海地区的河水和珠江入海口海水,采用聚合酶链反应(PCR)方法对样本检出的霍乱弧菌分离株进行霍乱肠毒素基因(ctx)、小带联结毒素基因(zot)、辅助霍乱肠毒素基因(ace)和毒力协同菌毛蛋白亚单位基因(tcpA)这4种毒力基因的检测,用随机扩增多态性分析(RAPD)结合SPSS软件对以上菌株进行多态性分析,对霍乱弧菌毒力进行快速测定并进行分子分型。结果 共采集海、水产品样本16 0份、水体样本90份,从样本中检出34株霍乱弧菌,其中分离自青蛙12株、虎纹蛙6株、牛蛙5株、养殖水5株、罗氏虾3株,其他3株,根据流行病学调查证实均为海南输入株。毒力基因检测表明,34株霍乱弧菌均未检出ctx和tcpA基因;14株菌(41% )可同时检出ace和zot基因,另有2株菌(6 % )只检出ace基因。所有34株霍乱弧菌的RAPD结果经聚类分析可分为2个聚类群,其中31株属于同一来源,只有3株菌与其他菌株的同源性有差异,但亲缘关系较近。结论 该次水产品监测的霍乱菌株均为非流行株,但仍需加强监测,预防霍乱流行株的出现而导致的霍乱散发和暴发流
Objective To understand the virulence characteristics of Vibrio cholerae isolates in the monitoring of aquatic products in Guangzhou and to analyze the homology of the strains and to study their molecular characteristics and epidemiological significance. Methods In June 2004, the seawater and aquatic products from three large aquatic products markets in Guangzhou and the seawater from estuaries and Pearl River estuaries in coastal areas where water cholera was endemic in Guangzhou were collected and analyzed by polymerase chain reaction (PCR) Methods Cholera toxin gene (ctx), zot, ace toxin, and tcpA genes were isolated from the V. cholerae isolates. The four virulence genes were detected by random amplified polymorphic (RAPD) combined with SPSS software for polymorphism analysis of the above strains, rapid determination of Vibrio cholerae virulence and molecular typing. Results A total of 160 samples of sea and fishery products and 90 samples of water samples were collected. Vibrio cholerae 34 strains were isolated from 12 samples, including 12 frogs, 6 tiger frogs, 5 bullfrogs and 5 breeding water. Roche shrimp 3, the other 3 strains, according to epidemiological survey confirmed that Hainan imported strains. Virulence genes showed no ctx and tcpA genes were detected in 34 strains of V. cholerae; ace and zot genes were detected in 14 strains (41%) and ace genes were detected in only 2 strains (6%) . All 34 V. cholerae RAPD results can be divided into two cluster groups by cluster analysis, of which 31 belong to the same source, only three strains of homology with other strains have different but close genetic relationship. Conclusion The cholera strains monitored by this aquatic product are all non-epidemic strains. However, monitoring and prevention of cholera outbreaks and outbreaks caused by the emergence of cholera epidemic strains are still needed