Parker Christopher T, Sperandio Vanessa
University of Texas Southwestern Medical Center, Dallas, TX 75390-9048, USA.
Cell Microbiol. 2009 Mar;11(3):363-9. doi: 10.1111/j.1462-5822.2008.01272.x.
Pathogenic bacteria produce virulence factors only when they sense they are in a location in which the energy required for pathogenesis is warranted. One environmental factor monitored by pathogens is population density, either of its own population or of the population of a host's endogenous flora. To date, four systems have been described which allow pathogens to regulate virulence genes in a population-dependent manner. These systems are found in both Gram-positive and Gram-negative cells and utilize various mechanisms to control gene regulation at a transcriptional level, but they all have one feature in common: they detect autoinducers released by cells belonging to either the pathogen's population or that of the host's flora. This article explores the role of these four signalling systems in bacterial communities and how pathogens use these systems to control genes required during host invasion and infection.
致病细菌只有在感知到自身所处位置具备发病所需能量时才会产生毒力因子。病原体监测的一个环境因素是种群密度，这既可以是其自身种群的密度，也可以是宿主内源性菌群的密度。迄今为止，已描述了四种系统，这些系统可使病原体以种群依赖的方式调节毒力基因。这些系统存在于革兰氏阳性菌和革兰氏阴性菌细胞中，并利用各种机制在转录水平上控制基因调控，但它们都有一个共同特征：它们能检测由病原体自身种群或宿主菌群中的细胞释放的自诱导物。本文探讨了这四种信号系统在细菌群落中的作用，以及病原体如何利用这些系统来控制宿主入侵和感染过程中所需的基因。
