Bacterial pathogens face stringent challenges to their survival because of the many unpredictable, often precipitate, and dynamic changes that occur in the host environment or in the process of transmission from one host to another. Bacterial adaptation to their hosts involves either a mechanism for sensing and responding to external changes or the selection of variants that arise through mutation. Here we review how bacterial pathogens exploit localized hypermutation, through polymerase slippage of simple sequence repeats (SSRs), to generate phenotypic variation and enhanced fitness. These SSRs are located within the reading frame or in the promoter of a subset of genes, often termed contingency loci, whose functions are usually involved in direct interactions with host structures.

中文翻译：

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细菌应急位点：简单序列 DNA 重复在细菌适应中的作用。

由于宿主环境或从一个宿主传播到另一个宿主的过程中发生了许多不可预测的、经常沉淀的和动态的变化，细菌病原体的生存面临着严峻的挑战。细菌对其宿主的适应涉及感知和响应外部变化的机制或选择通过突变产生的变体。在这里，我们回顾了细菌病原体如何通过简单序列重复 (SSR) 的聚合酶滑移利用局部超突变来产生表型变异和增强的适应性。这些 SSR 位于阅读框架内或位于基因子集的启动子中，通常称为偶然位点，其功能通常涉及与宿主结构的直接相互作用。