Disturbing the spatial structure of biofilms affects the expression of agr regulated virulence factors in Staphylococcus aureus

Staphylococcus aureus uses quorum sensing and nutrient availability to control the expression of agr-regulated virulence factors. Quorum sensing is mediated by autoinducing peptide (AIP), which at high concentration, reduces expression of surface attachment proteins (coa, fnbpA), and increases expression of exotoxins (lukS) and proteases (splA). Nutrient availability can be sensed through the saeS/saeR system. Low nutrients increase expression of saeR, which augments expression of coa and fnbpA distinct from AIP. The formation of spatial structure, such as biofilms, can alter quorum sensing and nutrient acquisition. In natural environments, biofilms encounter forces that may alter their spatial structure. This may impact quorum sensing and/or nutrient acquisition, and thus affect the expression of agr-regulated virulence factors. However, this has not been studied. We show that periodically disturbing biofilms composed of S. aureus using a physical force affects the expression of agr-re..., ,

金黄色葡萄球菌（Staphylococcus aureus）通过群体感应（quorum sensing）与营养可利用性调控agr调控的毒力因子的表达。群体感应由自诱导肽（autoinducing peptide，AIP）介导：当AIP浓度较高时，可降低表面附着蛋白（coa、fnbpA）的表达，并上调外毒素（lukS）与蛋白酶（splA）的转录。该菌可通过saeS/saeR系统感知营养可利用性状态：低营养条件会上调saeR的表达，进而独立于AIP途径，增强coa与fnbpA的表达。生物被膜（biofilms）这类空间结构的形成会改变群体感应与营养获取过程。在自然环境中，生物被膜会受到各类外力作用，进而改变其空间结构，这可能会影响群体感应或营养获取，最终影响agr调控的毒力因子的表达。但目前尚未有相关研究对此展开探究。本研究发现，通过物理外力周期性扰动由金黄色葡萄球菌（S. aureus）构成的生物被膜，会影响agr调控的……