霍乱弧菌中存在不含霍乱毒素基因的噬菌体CTXΦ基因组  

Genome of bacteriophage CTXΦ without the presence of ctxAB exists in ctxAB - strains of Vibrio cholerae

作　　者：阚飙[1,2] 祁国明[1,2] 刘延清[1,2] 刘彩莲 高守一[1,2] 

机构地区：[1]中国预防医学科学院流行病学微生物学研究所 [2]卫生部医学分子细菌学重点实验室

出　　处：《中华微生物学和免疫学杂志》1999年第3期175-179,共5页Chinese Journal of Microbiology and Immunology

摘　　要：目的近年研究发现产毒霍乱弧菌的毒素基因ｃｔｘＡＢ由其溶原性噬菌体ＣＴＸΦ编码，这种丝状噬菌体可携带ｃｔｘＡＢ传递给无毒素基因的霍乱菌株。研究认为ｃｔｘＡＢ基因与ＣＴＸΦ基因组中的其它基因是严格共存的。然而在本实验室研究中，于不含ｃｔｘＡＢ基因的ＥｌＴｏｒ型霍乱弧菌（ＥＶＣ）中发现部分菌株含有ＲＳ基因同源序列，为此对这些菌株作ＣＴＸΦ基因组的进一步研究。方法以ＣＴＸΦ基因组中的ｃｔｘＡ、ｃｔｘＢ、ｚｏｔ、ａｃｅ、ｃｅｐ和ＲＳ１结构基因制备探针，对ｃｔｘＡＢ－菌株染色体作Ｓｏｕｔｈｅｒｎｂｌｏｔ检测，并用ＰＣＲ方法检测ＣＴＸΦ的感染受体毒素共调菌毛（Ｔｃｐ）的ｔｃｐＡ基因。结果发现有４株分离自河水的霍乱毒素基因阴性ＥＶＣ菌株仍含有溶原噬菌体ＣＴＸΦ的基因组，为ｃｔｘＡ－ｃｔｘＢ－ｚｏｔ＋ａｃｅ＋ｃｅｐ＋ＲＳ＋菌株，另有一株分离自病人的ＥＶＣ菌株仅表现为ＲＳ＋。这些菌株均含ｔｃｐＡ基因。结论ｃｔｘＡＢ基因并不一定与ＣＴＸΦ其它基因共存于一个菌株中。Objective To research on the lysogenic bacteriophage CTXΦ genome, for isogenous sequences with RS in the chromosomes were found in some strains of ctxAB - E1 Tor biotype (EVC) isolates in this lab. Methods The DNA probes of CTXΦ genes, including ctxA , ctxB , zot , ace , cep and RS, were prepared and were used to detect the corresponding genes in the ctxAB - strains with Southern blot analysis. The major gene of CTXΦ receptor Tcp (toxin coregulated pilus), tcpA , was detected by polymerase chain reaction analysis. Results CTXΦ genome in the chromosomes were found in 4 isolates of ctxAB - EVC strains from water,and 1 isolate from a patient only possessed RS sequence. tcpA of all these strains was positive. Conclusions The results suggest that ctxAB may not has a concurrent occurrence with other CTXΦ genes. A novel CTXΦ genome without ctxAB gene presents in the chromosome of V. cholerae.

关 键 词：霍乱弧菌 霍乱毒素 CTXΦ基因组 

分 类 号：R378.3[医药卫生—病原生物学]