Role of the luxS quorum-sensing system in biofilm formation and virulence of Staphylococcus epidermidis.
Nosocomial infections caused by Staphylococcus epidermidis are 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 describe luxS, a quorum-sensing system in staphylococci that has a significant impact on biofilm development and virulence. We constructed an isogenic DeltaluxS mutant strain of a biofilm-forming clinical isolate of S. epidermidis and demonstrated that luxS signaling is functional in S. 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 that luxS repressed 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. The agr quorum-sensing system has previously been shown to impact biofilm development and biofilm-associated infection in a way similar to that of luxS, 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.
Xu
Lin
L
Key Laboratory of Medical Molecular Virology, Shanghai Medical College, Fudan University, Shanghai 200032, People's Republic of China.
Li
Hualin
H
Vuong
Cuong
C
Vadyvaloo
Viveka
V
Wang
Jianping
J
Yao
Yufeng
Y
Otto
Michael
M
Gao
Qian
Q
D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics / Q000502:physiology*; D018441:Biofilms / Q000254:growth & development*; D013437:Carbon-Sulfur Lyases; D003428:Cross Infection / Q000378:metabolism; D004195:Disease Models, Animal; D006714:Homoserine / Q000031:analogs & derivatives / Q000378:metabolism; D006801:Humans; D007783:Lactones / Q000378:metabolism; D008297:Male; D008855:Microscopy, Electron, Scanning; D009154:Mutation; D051381:Rats; D017207:Rats, Sprague-Dawley; D013203:Staphylococcal Infections / Q000378:metabolism* / Q000382:microbiology*; D013212:Staphylococcus epidermidis / Q000235:genetics / Q000472:pathogenicity* / Q000502:physiology* / Q000648:ultrastructure; D014774:Virulence
D001426:Bacterial Proteins; D007783:Lactones; C091088:N-octanoylhomoserine lactone; D006714:Homoserine; D013437:Carbon-Sulfur Lyases; C117753:LuxS protein, Bacteria