title: Effect of sub-inhibitory concentrations of antibiotics on the virulence of Staphylococcus aureus.
abstract: The production of virulence factors by various bacteria can be influenced by sub-inhibitory concentrations of antibiotics. The effect of six antibiotics on the production of representative extracellular enzymes and toxins produced by Staphylococcus aureus was investigated. The production of the virulence determinants coagulase, protein A, alpha and delta haemolysin was monitored in the presence of ciprofloxacin, enoxacin, chloramphenicol, gentamicin, tetracycline and methicillin. The protein synthesis inhibitors reduced the production of coagulase and protein A, and almost completely inhibited the production of the haemolysins. Haemolysin production was also reduced by ciprofloxacin and enoxacin, but these antibiotics had little effect on the production of coagulase and protein A. Methicillin stimulated the production of alpha and delta haemolysins but had no effect on the production of coagulase and protein A.
authors.affiliation: Department of Medical Microbiology, Medical School, University of Edinburgh, UK.
authors.forename: S A
authors.initials: SA
authors.lastname: Doss
authors.forename: G S
authors.initials: GS
authors.lastname: Tillotson
authors.forename: S G
authors.initials: SG
authors.lastname: Amyes
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D003030:Coagulase / Q000037:antagonists & inhibitors; D004305:Dose-Response Relationship, Drug; D006460:Hemolysin Proteins / Q000378:metabolism; D008826:Microbial Sensitivity Tests; D013205:Staphylococcal Protein A / Q000378:metabolism; D013211:Staphylococcus aureus / Q000187:drug effects* / Q000378:metabolism / Q000472:pathogenicity*; D014774:Virulence / Q000187:drug effects
chemical_list: D000900:Anti-Bacterial Agents; D003030:Coagulase; D006460:Hemolysin Proteins; D013205:Staphylococcal Protein A