title: Multiple combination bactericidal testing of staphylococcal biofilms from implant-associated infections.
abstract: Standardized susceptibility testing fails to predict in vivo resistance of device-related infections to antimicrobials. We assessed agents and combinations of antimicrobials against clinical isolates of Staphylococcus epidermidis and S. aureus (methicillin-resistant S. aureus and methicillin-sensitive S. aureus) retrieved from device-associated infections. Isolates were grown planktonically and as biofilms. Biofilm cultures of the organisms were found to be much more resistant to inhibitory and bactericidal effects of single and combination antibiotics than planktonic cultures (P < 0.001). Rifampin was the most common constituent of antibiotic combinations active against staphylococcal biofilms. Other frequently effective antimicrobials were vancomycin and fusidic acid. Susceptibility testing involving biofilm-associated bacteria suggests new options for combination antibiotic therapy.
authors.affiliation: Department of Medicine, CPC 470, The Ottawa Hospital, Civic Campus, 1053 Carling Avenue, Ottawa, ON K1Y 4E9. rsaginur@ohri.ca
authors.forename: Raphael
authors.initials: R
authors.lastname: Saginur
authors.forename: Melissa
authors.initials: M
authors.lastname: Stdenis
authors.forename: Wendy
authors.initials: W
authors.lastname: Ferris
authors.forename: Shawn D
authors.initials: SD
authors.lastname: Aaron
authors.forename: Francis
authors.initials: F
authors.lastname: Chan
authors.forename: Craig
authors.initials: C
authors.lastname: Lee
authors.forename: Karam
authors.initials: K
authors.lastname: Ramotar
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology* / Q000627:therapeutic use; D001422:Bacterial Adhesion; D018441:Biofilms / Q000254:growth & development*; D024881:Drug Resistance, Bacterial; D004359:Drug Therapy, Combination; D005672:Fusidic Acid / Q000494:pharmacology; D016106:Methicillin Resistance; D008826:Microbial Sensitivity Tests; D016459:Prosthesis-Related Infections / Q000188:drug therapy* / Q000382:microbiology; D012293:Rifampin / Q000494:pharmacology / Q000627:therapeutic use; D013203:Staphylococcal Infections / Q000382:microbiology; D013211:Staphylococcus aureus / Q000187:drug effects* / Q000302:isolation & purification / Q000502:physiology; D013212:Staphylococcus epidermidis / Q000187:drug effects* / Q000302:isolation & purification / Q000502:physiology
chemical_list: D000900:Anti-Bacterial Agents; D005672:Fusidic Acid; D012293:Rifampin