title: Impact of the accessory gene regulatory system (Agr) on extracellular proteins, codY expression and amino acid metabolism in Staphylococcus epidermidis.
abstract: The quorum-sensing system Agr is part of a complex regulatory network of gene expression in staphylococci. This study presents the effect of an agr mutation on a biofilm-forming Staphylococcus epidermidis isolate by employing proteome and transcriptome analysis. The agr mutant exhibited a significantly lowered amount of extracellular proteins: amongst others SspA, AtlE, GehD and the phenol soluble modulins PSM1/2. Cytoplasmic proteome analysis and expression profiling indicated that the agr inactivation led to a strongly altered regulation of metabolism and virulence. Most strikingly, expression of CodY, a global regulator of virulence and stationary phase gene expression, was decreased in the agr mutant. In this respect, homologous genes known to be controlled by CodY in Bacillus subtilis and Lactococcus lactis were found to be up-regulated in the S. epidermidis agr mutant. The combined data show that wild-type and agr mutant differ with respect to amino acid biosynthesis and oligopeptide transport, carbohydrate utilization, as well as GMP and IMP interconversion. Due to the varying physiological properties S. epidermidis agr mutants, which often occur spontaneously, might be capable of colonizing alternative ecological niches in the human host and could, therefore, have an advantage in adapting to changing environmental conditions.
authors.affiliation: Institut für Molekulare Infektionsbiologie, Universität Würzburg, Germany.
authors.forename: Christoph F
authors.initials: CF
authors.lastname: Batzilla
authors.forename: Shwan
authors.initials: S
authors.lastname: Rachid
authors.forename: Susanne
authors.initials: S
authors.lastname: Engelmann
authors.forename: Michael
authors.initials: M
authors.lastname: Hecker
authors.forename: Jörg
authors.initials: J
authors.lastname: Hacker
authors.forename: Wilma
authors.initials: W
authors.lastname: Ziebuhr
mesh_terms: D000596:Amino Acids / Q000378:metabolism*; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism*; D018441:Biofilms / Q000254:growth & development*; D003593:Cytoplasm / Q000737:chemistry / Q000378:metabolism; D004269:DNA, Bacterial / Q000032:analysis; D015180:Electrophoresis, Gel, Two-Dimensional; D020869:Gene Expression Profiling; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial; D006801:Humans; D009154:Mutation; D009693:Nucleic Acid Hybridization; D020411:Oligonucleotide Array Sequence Analysis; D010446:Peptide Fragments / Q000737:chemistry; D010449:Peptide Mapping; D020543:Proteome / Q000032:analysis; D013212:Staphylococcus epidermidis / Q000235:genetics / Q000254:growth & development* / Q000302:isolation & purification / Q000378:metabolism; D014158:Transcription, Genetic
chemical_list: D000596:Amino Acids; D001426:Bacterial Proteins; D004269:DNA, Bacterial; D010446:Peptide Fragments; D020543:Proteome