title: False synergy between vancomycin and beta-lactams against glycopeptide-intermediate Staphylococcus aureus (GISA) caused by inappropriate testing methods.
abstract: The combination of vancomycin and beta-lactams is often considered synergistic and has been recommended for the treatment of glycopeptide-intermediate Staphylococcus aureus (GISA) infections. In this study, the combination of vancomycin or teicoplanin with different beta-lactams was tested. When using NaCl 4% w/v, for better expression of heterogeneous resistance to beta-lactams, with a longer (48-h) incubation period and a higher (10(7) CFU/mL) inoculum, the association of vancomycin with beta-lactams was antagonistic. However, a synergistic effect was observed for teicoplanin under the same conditions.
authors.affiliation: Fondation Hospital Saint-Joseph, 185 rue Raymond Losserand, 75014 Paris, France. fgoldstein@hospital-saint-joseph.org
authors.forename: F W
authors.initials: FW
authors.lastname: Goldstein
authors.forename: R
authors.initials: R
authors.lastname: Atoui
authors.forename: A
authors.initials: A
authors.lastname: Ben Ali
authors.forename: J C
authors.initials: JC
authors.lastname: Nguyen
authors.forename: A
authors.initials: A
authors.lastname: Ly
authors.forename: M D
authors.initials: MD
authors.lastname: Kitzis
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D004357:Drug Synergism; D005189:False Positive Reactions; D006801:Humans; D008826:Microbial Sensitivity Tests / Q000379:methods; D013211:Staphylococcus aureus / Q000187:drug effects*; D017334:Teicoplanin / Q000494:pharmacology*; D014640:Vancomycin / Q000494:pharmacology*; D047090:beta-Lactams / Q000494:pharmacology*
chemical_list: D000900:Anti-Bacterial Agents; D047090:beta-Lactams; D017334:Teicoplanin; D014640:Vancomycin