Iyobe S
Laboratory of Drug-Resistance in Bacteria, Gunma University School of Medicine.
Nihon Rinsho. 1997 May;55(5):1179-84.
Pathogenic bacteria acquire resistance to chemotherapeutic agents by mutational events in the intrinsic genes or by incorporating foreign resistance genes. The resistance genes to various drugs were transferred among bacteria by transformation with free DNA, phage-mediated transduction, or cell to cell conjugation. Plasmids are capable of self-replication and self-transfer by conjugation. Drug-resistance genes are incorporated into plasmids by transposable elements, transposons. Several kinds of transposons carrying resistance genes to various drugs, or some transposons carrying multiresistance genes, are mobile among genetic elements and confer multiresistance on pathogenic bacteria. There is a specific element, integron, on transposons or plasmids. The integron has the gene and the site for incorporating resistance genes as cassettes and allows expression of the genes.
致病细菌通过内在基因的突变事件或通过整合外来耐药基因获得对化疗药物的抗性。各种药物的耐药基因通过游离DNA转化、噬菌体介导的转导或细胞间接合在细菌之间转移。质粒能够通过接合进行自我复制和自我转移。耐药基因通过转座元件（转座子）整合到质粒中。几种携带各种药物耐药基因的转座子，或一些携带多重耐药基因的转座子，在遗传元件之间移动并赋予致病细菌多重耐药性。转座子或质粒上有一个特定元件，即整合子。整合子具有作为盒式结构整合耐药基因的基因和位点，并允许这些基因表达。
