Role of theluxSQuorum-Sensing System in Biofilm Formation and Virulence ofStaphylococcus epidermidis

• DOI: 10.1128/iai.74.1.488-496.2006
• Publication Date: 2005-12-20T22:02:58Z
• Authors: Lin Xu; Hualin Li; Cuong Vuong; Viveka Vadyvaloo; Jianping Wang; Yufeng Yao; Michael Otto; Qian Gao
• Keywords: Male; 0301 basic medicine; Cross Infection; Virulence; Staphylococcal Infections; Rats; 3. Good health; Rats, Sprague-Dawley; Carbon-Sulfur Lyases; Disease Models, Animal; Lactones; 03 medical and health sciences; Bacterial Proteins; Biofilms; Mutation; Homoserine; Microscopy, Electron, Scanning; Staphylococcus epidermidis; Animals; Humans

ABSTRACTNosocomial infections caused byStaphylococcus epidermidisare characterized by biofilm formation on implanted medical devices. Quorum-sensing regulation plays a major role in the biofilm development of many bacterial pathogens. Here, we describeluxS, a quorum-sensing system in staphylococci that has a significant impact on biofilm development and virulence. We constructed an isogenicΔluxSmutant strain of a biofilm-forming clinical isolate ofS. epidermidisand demonstrated thatluxSsignaling is functional inS. epidermidis. The mutant strain showed increased biofilm formation in vitro and enhanced virulence in a rat model of biofilm-associated infection. Genetic complementation and addition of autoinducer 2-containing culture filtrate restored the wild-type phenotype, demonstrating thatluxSrepressed biofilm formation through a cell-cell signaling mechanism based on autoinducer 2 secretion. Enhanced production of the biofilm exopolysaccharide polysaccharide intercellular adhesin in the mutant strain is presumably the major cause of the observed phenotype. Theagrquorum-sensing system has previously been shown to impact biofilm development and biofilm-associated infection in a way similar to that ofluxS, although by regulation of different factors. Our study indicates a general scheme of quorum-sensing regulation of biofilm development in staphylococci, which contrasts with that observed in many other bacterial pathogens.