Kaper J B, Bradford H B, Roberts N C, Falkow S
J Clin Microbiol. 1982 Jul;16(1):129-34. doi: 10.1128/jcm.16.1.129-134.1982.
Enterotoxigenic strains of Vibrio cholerae O-1, biotype El Tor, isolated from a case of cholera in Texas in 1973, an outbreak of cholera in Louisiana in 1978, and Louisiana sewage samples in 1980 and 1981 were analyzed for their genetic similarities. Chromosomal DNA was isolated from each strain, digested with restriction endonuclease, and analyzed by the Southern blot technique. A radioactive probe consisting of Escherichia coli heat-labile enterotoxin DNA detected cholera toxin gene sequences in these strains and demonstrated that the toxin gene sequence, if not the entire chromosomal DNA, is identical in these strains and distinctly different from other strains of V. cholerae isolated throughout the world. In addition, two strains of enterotoxigenic V. cholerae non-O-1 isolated from clinical cases, were analyzed and found to possess cholera toxin genes which differed in the DNA sequence from the V. cholerae O-1 strains. We concluded that a single strain of enterotoxigenic V. cholerae O-1 is resident in the U.S. Gulf Coast and that a second reservoir of cholera toxin genes exists in V. cholerae non-O-1 strains in Louisiana.
对1973年从得克萨斯州的一例霍乱病例中分离出的霍乱弧菌O-1型、埃尔托生物型产肠毒素菌株，1978年路易斯安那州霍乱疫情中分离出的菌株，以及1980年和1981年路易斯安那州污水样本中的菌株进行了遗传相似性分析。从每个菌株中分离出染色体DNA，用限制性内切酶消化，并通过Southern印迹技术进行分析。由大肠杆菌不耐热肠毒素DNA组成的放射性探针检测到这些菌株中的霍乱毒素基因序列，并表明这些菌株中的毒素基因序列（如果不是整个染色体DNA）是相同的，且与从世界各地分离出的其他霍乱弧菌菌株明显不同。此外，对从临床病例中分离出的两株产肠毒素非O-1型霍乱弧菌进行了分析，发现它们拥有的霍乱毒素基因在DNA序列上与霍乱弧菌O-1型菌株不同。我们得出结论，在美国墨西哥湾沿岸存在单一的产肠毒素霍乱弧菌O-1型菌株，并且在路易斯安那州的非O-1型霍乱弧菌菌株中存在霍乱毒素基因的第二个储存库。
