title: The role of polysaccharide intercellular adhesin (PIA) in Staphylococcus epidermidis adhesion to host tissues and subsequent antibiotic tolerance.
abstract: The aim of this study was to determine the role of polysaccharide intercellular adhesin (PIA) in Staphylococcus epidermidis adhesion to host tissues and subsequent antibiotic tolerance. The adherence of S. epidermidis 1457 and the mutant defective in PIA production (1457-M10) to urinary epithelium and endothelium was estimated by colony counting. Minimum bactericidal concentration and mean reduction of cellular activity (XTT) following antibiotic exposure was determined for planktonic and adhered bacteria. S. epidermidis 1457 adhered to a greater extent to both cells than the mutant strain. The adhered strains had a significantly higher antimicrobial tolerance than their planktonic counterparts. The mutant strain was, in general, the most susceptible to the antibiotics assayed. In conclusion, PIA may influence S. epidermidis adherence to host tissues and their antimicrobial susceptibility. Initial adhesion may be the main step for the acquisition of resistance in S. epidermidis.
authors.affiliation: IBB-Institute for Biotechnology and Bioengineering, Centre of Biological Engineering, Universidade do Minho, 4710-057, Braga, Portugal.
authors.forename: A R
authors.initials: AR
authors.lastname: Costa
authors.forename: M
authors.initials: M
authors.lastname: Henriques
authors.forename: R
authors.initials: R
authors.lastname: Oliveira
authors.forename: J
authors.initials: J
authors.lastname: Azeredo
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001422:Bacterial Adhesion; D002460:Cell Line; D042783:Endothelial Cells / Q000382:microbiology; D004847:Epithelial Cells / Q000382:microbiology; D006801:Humans; D008826:Microbial Sensitivity Tests; D050296:Microbial Viability; D009154:Mutation; D011135:Polysaccharides, Bacterial / Q000235:genetics / Q000502:physiology*; D013212:Staphylococcus epidermidis / Q000187:drug effects* / Q000472:pathogenicity*; D013778:Tetrazolium Salts / Q000378:metabolism
chemical_list: D000900:Anti-Bacterial Agents; D011135:Polysaccharides, Bacterial; D013778:Tetrazolium Salts; C113579:polysaccharide intercellular adhesin; C059087:2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-5-((phenylamino)carbonyl)-2H-tetrazolium hydroxide