title: The two-component signal transduction system ArlRS regulates Staphylococcus epidermidis biofilm formation in an ica-dependent manner.
abstract: Due to its ability to form biofilms on medical devices, Staphylococcus epidermidis has emerged as a major pathogen of nosocomial infections. In this study, we investigated the role of the two-component signal transduction system ArlRS in regulating S. epidermidis biofilm formation. An ArlRS-deficient mutant, WW06, was constructed using S. epidermidis strain 1457 as a parental strain. Although the growth curve of WW06 was similar to that of SE1457, the mutant strain was unable to form biofilms in vitro. In a rabbit subcutaneous infection model, sterile disks made of polymeric materials were implanted subcutaneously followed with inoculation of WW06 or SE1457. The viable bacteria cells of WW06 recovered from biofilms on the embedded disks were much lower than that of SE1457. Complementation of arlRS genes expression from plasmid in WW06 restored biofilm-forming phenotype both in vivo and in vitro. WW06 maintained the ability to undergo initial attachment. Transcription levels of several genes involved in biofilm formation, including icaADBC, sigB, and sarA, were decreased in WW06, compared to SE1457; and icaR expression was increased in WW06, detected by real-time reverse-transcription PCR. The biofilm-forming phenotype was restored by overexpressing icaADBC in WW06 but not by overexpressing sigB, indicating that ArlRS regulates biofilm formation through the regulation of icaADBC. Gel shift assay showed that ArlR can bind to the promoter region of the ica operon. In conclusion, ArlRS regulates S. epidermidis biofilm formation in an ica-dependent manner, distinct from its role in S. aureus.
authors: Key Laboratory of Medical Molecular Virology of the Ministry of Education and Ministry of Public Health, Institute of Medical Microbiology, Shanghai Medical College of Fudan University, Shanghai, PR China.
authors: Yang
authors: Y
authors: Wu
authors: Jiaxue
authors: J
authors: Wang
authors: Tao
authors: T
authors: Xu
authors: Jingran
authors: J
authors: Liu
authors: Wenqi
authors: W
authors: Yu
authors: Qiang
authors: Q
authors: Lou
authors: Tao
authors: T
authors: Zhu
authors: Nianan
authors: N
authors: He
authors: Haijing
authors: H
authors: Ben
authors: Jian
authors: J
authors: Hu
authors: Friedrich
authors: F
authors: Götz
authors: Di
authors: D
authors: Qu
mesh_terms: D001422:Bacterial Adhesion / Q000502:physiology; D001426:Bacterial Proteins / Q000096:biosynthesis* / Q000235:genetics; D018441:Biofilms / Q000254:growth & development*; D004268:DNA-Binding Proteins / Q000096:biosynthesis* / Q000235:genetics; D015964:Gene Expression Regulation, Bacterial / Q000502:physiology*; D009154:Mutation; D015398:Signal Transduction / Q000502:physiology*; D013212:Staphylococcus epidermidis / Q000502:physiology*
chemical_list: D001426:Bacterial Proteins; D004268:DNA-Binding Proteins