title: Comparison of biofilm-associated cell survival following in vitro exposure of meticillin-resistant Staphylococcus aureus biofilms to the antibiotics clindamycin, daptomycin, linezolid, tigecycline and vancomycin.
abstract: The efficacy of commonly used antistaphylococcal antimicrobials (clindamycin, linezolid and vancomycin) and recently developed antibiotics (daptomycin and tigecycline) was compared against clinical isolates of meticillin-resistant Staphylococcus aureus (MRSA). Minimum inhibitory concentrations (MICs), minimum bactericidal concentrations, time-kill kinetics and biofilm-associated cell survival were examined for 12 clinical isolates of MRSA treated with each antibiotic. The MIC ranges for daptomycin, linezolid, tigecycline, clindamycin and vancomycin were 0.06-0.25, 1-2, 0.06, 0.125-1024 and 0.5-1 microg/mL, respectively. Daptomycin and vancomycin were bactericidal following 6h of incubation with planktonic cells, whilst clindamycin, linezolid and tigecycline were bacteriostatic. None of the antibiotics killed 100% of biofilm-associated cells. Mean cell survival in biofilms treated with clindamycin, daptomycin, linezolid, tigecycline and vancomycin was 62%, 4%, 45%, 43% and 19%, respectively. Although all antibiotics were effective against planktonic staphylococcal populations, vancomycin and daptomycin possessed superior activity against biofilm-associated cells.
authors.affiliation: Department of Biological and Biomedical Sciences, Glasgow Caledonian University, Glasgow, UK.
authors.forename: Karen
authors.initials: K
authors.lastname: Smith
authors.forename: Ana
authors.initials: A
authors.lastname: Perez
authors.forename: Gordon
authors.initials: G
authors.lastname: Ramage
authors.forename: Curtis G
authors.initials: CG
authors.lastname: Gemmell
authors.forename: Sue
authors.initials: S
authors.lastname: Lang
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D018441:Biofilms / Q000187:drug effects*; D006801:Humans; D055624:Methicillin-Resistant Staphylococcus aureus / Q000187:drug effects* / Q000302:isolation & purification; D008826:Microbial Sensitivity Tests; D050296:Microbial Viability / Q000187:drug effects*; D013203:Staphylococcal Infections / Q000382:microbiology; D013997:Time Factors
chemical_list: D000900:Anti-Bacterial Agents