title: In vitro effect of levofloxacin and vancomycin combination against high level aminoglycoside-resistant enterococci.
abstract: The in vitro effects of levofloxacin and vancomycin in combination were evaluated against high level aminoglycoside-resistant (HLAR) enterococci using chequerboard and time-kill curve techniques. We examined 28 strains of enterococci comprising 17 Enterococcus faecalis, 10 E. faecium and one E. durans. The combination of vancomycin and levofloxacin had indifferent activity against all isolates according to chequerboard microdilution method, but was synergistic for two isolates, one E. faecium and one E. faecalis, using the time-kill curve method. Both strains were levofloxacin resistant and had high level aminoglycoside resistance to gentamicin and streptomycin. Antagonism was not detected in any strain. The results of this study suggested that the combination of vancomycin with levofloxacin does not often show synergistic effect against high level aminoglycoside-resistant enterococci.
authors.affiliation: Clinic of Infectious Disease and Clinical Microbiology, Haydarpasa Numune Training and Research Hospital, Nuhkuyusu Cad. Gencsuer Apt No 153/4, 81150 Baglarbasi, Istanbul, Turkey. ilknurerdem@hotmail.com
authors.forename: Ilknur
authors.initials: I
authors.lastname: Erdem
authors.forename: Gonul
authors.initials: G
authors.lastname: Cicek-Senturk
authors.forename: Behiye
authors.initials: B
authors.lastname: Yucesoy-Dede
authors.forename: Funda
authors.initials: F
authors.lastname: Yuksel-Kocdogan
authors.forename: Saim
authors.initials: S
authors.lastname: Yuksel
authors.forename: Emin
authors.initials: E
authors.lastname: Karagul
mesh_terms: D000617:Aminoglycosides; D024881:Drug Resistance, Bacterial; D004359:Drug Therapy, Combination; D013293:Enterococcus faecalis / Q000187:drug effects* / Q000302:isolation & purification; D016984:Enterococcus faecium / Q000187:drug effects* / Q000302:isolation & purification; D066298:In Vitro Techniques; D064704:Levofloxacin; D015242:Ofloxacin / Q000494:pharmacology*; D014640:Vancomycin / Q000494:pharmacology*; D018440:beta-Lactam Resistance
chemical_list: D000617:Aminoglycosides; D064704:Levofloxacin; D014640:Vancomycin; D015242:Ofloxacin