2001年至2005年廣州地區霍亂弧菌主要致病相關基因特征分析
Analysis of characteristics of major pathogenicity-related genes of Vibrio cholerae isolated in
作者：王鳴；李孝權；莫自耀；劉于飛；鄧志愛；沈紀川；張欣強
機構：廣州市疾病預防控制中心
【摘要】 目的 應用多重聚合酶鏈反應（PCR）檢測方法和測序研究近5年廣州地區分離的霍亂弧菌的4種致病相關基因的攜帶情況及霍亂腸毒素基因ctxA的變異情況。方法 針對霍亂腸毒素A亞單位基因（ctxA）、小帶聯結毒素基因（zot）、輔助霍亂腸毒素基因（ace）、毒素共調菌毛亞單位A基因（tcpA）設計引物，將多重PCR方法應用于廣州地區分離的276株霍亂弧菌的致病相關基因的檢測。對ctxA基因的PCR擴增產物進行核酸序列測定，探討ctxA擴增產物的同源性。結果 近5年廣州地區分離的276株霍亂弧菌中，人源株中93.9%為致病相關基因A型（ctxA+tcpA+ace+zot+型）菌，其余6.1%為致病相關基因C型（ctxA-tcpA-ace-zot-型）菌，臨床分離的致病相關基因A型菌分離自輕、中、重型病例和帶菌者，其中有68.5%分離自輕型病例，21.9%分離自帶菌者，臨床分離的致病相關基因C型菌中有63.6%分離自輕型病例，36.4%分離自帶菌者，C型菌引起帶菌者的比例高于A型菌；78株環境分離株中9.0%為致病相關基因A型菌，35.9%為致病相關基因B型（ctxA-tcpA-ace+zot+型）菌，55.1%為致病相關基因C型菌。霍亂腸毒素基因ctxA變異較小。結論 多重PCR方法揭示了廣州地區霍亂弧菌致病相關基因模式的多態性，為深入研究人源和環境來源霍亂菌株致病相關基因的演化提供了有效手段，并對本地區霍亂的預防、控制和預警具有重要的指導意義。
【Abstract】 Objective To apply mutiplex polymerase chain reaction (MPCR) assay and sequencing in study of the carrying status of four pathogenicity-related genes of Vibrio cholerae(V.cholerae) and the variation of ctxA. Methods Primers targeting cholera toxin sub-unit A gene(ctxA), toxin-coregulate pilus gene(tcpA), accessory cholera enterotoxin gene(ace), zonula occludens toxin gene(zot) were designed and the MPCR method was applied to detect the pathogenicity-related genes of 276 strains of the V.cholerae isolates. The amplified fragments of ctxA gene were sequenced and the genetic homology of the amplified fragments of ctxA was analyzed. Results Of the 276 strains of V.cholerae, 93.9% strains from human sources belong to the pathogenicity-related gene type A(ctxA+tcpA+ace+zot+ type) and 6.1% belong to pathogenicity-related genes type C (ctxA-tcpA-ace-zot- type). Type A strains from clinical sources were isolated from patients with mild to severe symptom and carries, among which 68.5% were isolated from patients with mild symptom and 21.9% from carries. All 63.6% of type C strains from clinical sources were isolate from patients with mild symptom and 36.4% from carriers. The proportion of type C strains that caused mild symptom was higher than that of type A strains. Of the 78 strains isolate from the environment, 9.0% strains belong to pathogenicity-related type A and 35.9% belong to the pathogenicity-related genes type B (ctxA-tcpA-ace+zot+ type), while 55.1% belong to pathogenicity-related gene type C. The sequencing results showed little genetic variation among the amplified fragments for ctxA. Conclusion MPCR disclosed the polymorphic status of pathogenicity-related gene patterns in V.cholerae isolate of
【關鍵詞】 霍亂弧菌，霍亂；聚合酶鏈反應；序列分析；基因型；霍亂弧菌
【Key words】 Vibrio cholerae, cholera; Polymerase chain reaction; Sequence analysis; Genotype; Cholera toxin
中文刊名：中華預防醫學雜志, 2006年 04期
