Identification of Three Essential Regulatory Gene Loci Governing Expression of Staphylococcus epidermidis Polysaccharide Intercellular Adhesin and Biofilm Formation

摘要: The formation of adherent multilayered biofilms embedded into a glycocalyx represents an essential factor in the pathogenesis Staphylococcus epidermidis biomaterial-related infections. Using biofilm-producing S. 1457 and transposon Tn917 carried on plasmid pTV1ts, we isolated nine isogenic biofilm-negative mutants. Transduction by phage 71 was used to prove genetic linkage insertions altered phenotypes. Mapping different Southern hybridization pulsed-field gel electrophoresis indicated that these were inserted four unlinked loci. According their phenotypes, including quantitative differences biofilm production growth media, amount polysaccharide intercellular adhesin (PIA) produced, hemagglutination titers, colony morphology, mutants could be separated phenotypic classes corresponding with classes. Synthesis PIA not detectable class I II mutants, whereas produced reflected residual degree III IV media. Chromosomal DNA flanking five cloned sequenced, mapped locations icaADBC, representing synthetic genes for PIA. Expression icaADBC from xylose-dependent promoter mutant reconstituted all In Northern blot analysis no icaADBC-specific transcripts observed RNA II, III, IV. Apparently, addition three other gene loci have direct or indirect regulatory influence expression level transcription.