Chu Weihua, Vattem Dhiraj A, Maitin Vatsala, Barnes Mary B, McLean Robert J C
Department of Biology, Texas State University-San Marcos, San Marcos, TX, USA.
Methods Mol Biol. 2011;692:3-19. doi: 10.1007/978-1-60761-971-0_1.
In most bacteria, a global level of regulation exists involving intercellular communication via the production and response to cell density-dependent signal molecules. This cell density-dependent regulation has been termed quorum sensing (QS). QS is a global regulator, which has been associated with a number of important features in bacteria including virulence regulation and biofilm formation. Consequently, there is considerable interest in understanding, detecting, and inhibiting QS. Acyl homoserine lactones (acyl HSLs) are used as extracellular QS signals by a variety of Gram-negative bacteria. Chromobacterium violaceum, a Gram-negative bacterium commonly found in soil and water, produces the characteristic purple pigment violacein, the production of which is regulated by acyl HSL-mediated QS. Based on this readily observed pigmentation phenotype, C. violaceum strains can be used to detect various aspects of acyl HSL-mediated QS activity. In another commonly used bioassay organism, Agrobacterium tumefaciens, QS can be detected by the use of a reporter gene such as lacZ. Here, we describe several commonly used approaches incorporating C. violaceum and A. tumefaciens that can be used to detect acyl HSLs and QS inhibition.
在大多数细菌中，存在一种全局水平的调控，涉及通过产生和响应细胞密度依赖性信号分子进行细胞间通讯。这种细胞密度依赖性调控被称为群体感应（QS）。QS是一种全局调节因子，与细菌中的许多重要特征相关，包括毒力调节和生物膜形成。因此，人们对理解、检测和抑制QS有着浓厚的兴趣。酰基高丝氨酸内酯（酰基HSLs）被多种革兰氏阴性细菌用作细胞外QS信号。紫色杆菌是一种常见于土壤和水中的革兰氏阴性细菌，能产生特征性紫色色素紫菌素，其产生受酰基HSL介导的QS调控。基于这种易于观察到的色素沉着表型，紫色杆菌菌株可用于检测酰基HSL介导的QS活性的各个方面。在另一种常用的生物测定生物体根癌土壤杆菌中，可通过使用报告基因如lacZ来检测QS。在此，我们描述了几种结合紫色杆菌和根癌土壤杆菌的常用方法，可用于检测酰基HSLs和QS抑制。
