title: Modulation of cell wall synthesis and susceptibility to vancomycin by the two-component system AirSR in Staphylococcus aureus NCTC8325.
abstract: BACKGROUND
  Vancomycin has been the medication of last resort to cure infections caused by Staphylococcus aureus since the increase in the prevalence of methicillin-resistant Staphylococcus aureus (MRSA). Some strains have developed vancomycin-intermediate resistance, which is generally associated with altered expression of or mutations in some part of the two-component system (TCS), such as GraSR, VraSR, and WalKR.
  
  
  RESULTS
  We deleted the AirSR TCS in S. aureus NCTC8325 and compared the resultant transcript levels with those of its parent strain using microarray analysis. The results indicated that more than 20 genes that are related to cell wall metabolism were down-regulated in the airSR mutant. The airSR mutant exhibited reduced autolysis rates and reduced viability in the presence of vancomycin. Real-time reverse transcription PCR and DNA mobility shift assays verified that AirR can directly bind to and regulate genes that function in cell wall metabolism (cap, pbp1, and ddl) and autolysis (lytM).
  
  
  CONCLUSIONS
  AirSR acts as a positive regulator in cell wall biosynthesis and turnover in Staphylococcus aureus NCTC8325.
authors: Haipeng
authors: H
authors: Sun
authors: Yifan
authors: Y
authors: Yang
authors: Department of Microbiology and Immunology, School of Life Sciences, University of Science and Technology of China, Huangshan Road, Hefei, Anhui 230027, China. xueting@ustc.edu.cn.
authors: Ting
authors: T
authors: Xue
authors: Baolin
authors: B
authors: Sun
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001433:Bacteriolysis / Q000187:drug effects; D002473:Cell Wall / Q000378:metabolism*; D024202:Electrophoretic Mobility Shift Assay; D017353:Gene Deletion; D020869:Gene Expression Profiling; D015964:Gene Expression Regulation, Bacterial; D006801:Humans; D008826:Microbial Sensitivity Tests; D050296:Microbial Viability / Q000187:drug effects; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction; D013211:Staphylococcus aureus / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism; D014158:Transcription, Genetic; D014640:Vancomycin / Q000494:pharmacology*; D020713:Vancomycin Resistance
chemical_list: D000900:Anti-Bacterial Agents; D014640:Vancomycin