Van Cuyck-Gandre H, Negre D, Micard D, Cozzone A J, Cenatiempo Y
Division de Microbiologie, Centre de Recherche du Service de Santé des Armées, Lyon, France.
Pathol Biol (Paris). 1987 Sep;35(7):1027-32.
Bacterial resistance to mercury has been studied in two different strains from animal origin, Salmonella typhimurium 9205 and Escherichia coli 467. These two strains are resistant to mercuric chloride but sensitive to phenylmercury, and thus belong to the group of bacteria that possess a "narrow" spectrum resistance. The presence of plasmids within the cells has been demonstrated through conjugation experiments and direct detection of extrachromosomal DNA in transconjugants. These plasmids, termed p9205-1 and p467-30, differ from each other by both their size (100 and 50 Kbp, respectively) and structure, as shown by the restriction patterns arising from digestion by nucleases BamHI, HindIII, PstI and EcoRI. Each plasmid has been treated with enzyme SalI to yield DNA fragments that have been cloned into pBR322. Two recombinant plasmids, p9205-1/Sal and p467-30/Sal, have thus been constructed, each of them harboring a 2 Kbp fragment that appears to contain the merA gene coding for mercuric reductase. From the analysis of the restriction maps of these recombinant plasmids as well as the functional behaviour of the bacteria that they are able to transform, it can be concluded that they are identical.
对来自动物源的两种不同菌株——鼠伤寒沙门氏菌9205和大肠杆菌467——的汞抗性进行了研究。这两种菌株对氯化汞具有抗性，但对苯基汞敏感，因此属于具有“窄”谱抗性的细菌群体。通过接合实验和直接检测转接合子中的染色体外DNA，已证明细胞内存在质粒。这些质粒分别称为p9205 - 1和p467 - 30，它们在大小（分别为100和50千碱基对）和结构上彼此不同，这由核酸酶BamHI、HindIII、PstI和EcoRI消化产生的限制性图谱所示。每个质粒都用SalI酶处理以产生已克隆到pBR322中的DNA片段。由此构建了两个重组质粒，p9205 - 1/Sal和p467 - 30/Sal，它们各自携带一个似乎包含编码汞还原酶的merA基因的2千碱基对片段。从对这些重组质粒的限制性图谱分析以及它们能够转化的细菌的功能行为可以得出结论，它们是相同的。
