Rouch D A, Lee B T, Morby A P
School of Biological Sciences, University of Birmingham, Edgbaston, UK.
J Ind Microbiol. 1995 Feb;14(2):132-41. doi: 10.1007/BF01569895.
Bacterial resistances to metals are heterogeneous in both their genetic and biochemical bases. Metal resistance may be chromosomally-, plasmid- or transposon-encoded, and one or more genes may be involved: at the biochemical level at least six different mechanisms are responsible for resistance. Various types of resistance mechanisms can occur singly or in combination and for a particular metal different mechanisms of resistance can occur in the same species. To understand better the diverse responses of bacteria to metal ion challenge we have constructed a qualitative model for the selection of metal resistance in bacteria. How a bacterium becomes resistant to a particular metal depends on the number and location of cellular components sensitive to the specific metal ion. Other important selective factors include the nature of the uptake systems for the metal, the role and interactions of the metal in the normal metabolism of the cell and the availability of plasmid (or transposon) encoded resistance mechanisms. The selection model presented is based on the interaction of these factors and allows predictions to be made about the evolution of metal resistance in bacterial populations. It also allows prediction of the genetic basis and of mechanisms of resistance which are in substantial agreement with those in well-documented populations. The interaction of, and selection for resistance to, toxic substances in addition to metals, such as antibiotics and toxic analogues, involve similar principles to those concerning metals. Potentially, models for selection of resistance to any substance can be derived using this approach.
细菌对金属的抗性在遗传和生化基础上都是异质的。金属抗性可能由染色体、质粒或转座子编码，可能涉及一个或多个基因：在生化水平上，至少有六种不同机制负责抗性。各种类型的抗性机制可以单独出现或组合出现，对于特定金属，同一物种中可能会出现不同的抗性机制。为了更好地理解细菌对金属离子挑战的不同反应，我们构建了一个细菌中金属抗性选择的定性模型。细菌如何对特定金属产生抗性取决于对特定金属离子敏感的细胞成分的数量和位置。其他重要的选择因素包括金属的摄取系统的性质、金属在细胞正常代谢中的作用和相互作用以及质粒（或转座子）编码的抗性机制的可用性。所提出的选择模型基于这些因素的相互作用，并允许对细菌群体中金属抗性的进化进行预测。它还允许预测抗性的遗传基础和机制，这与有充分记录的群体中的情况基本一致。除金属外，对有毒物质（如抗生素和有毒类似物）的抗性的相互作用和选择涉及与金属相关的类似原则。潜在地，可以使用这种方法推导出对任何物质抗性选择的模型。
