title: In vitro evaluation of the antimicrobial activity of meropenem in combination with polymyxin B and gatifloxacin against Pseudomonas aeruginosa and Acinetobacter baumannii.
abstract: The antimicrobial activity of meropenem combined with either polymyxin B or gatifloxacin was evaluated by the checkerboard method against Pseudomonas aeruginosa (10 strains) and Acinetobacter baumannii (10 strains). In addition, the triple combination of polymyxin B, gatifloxacin, and meropenem was also studied as well as the polymyxin B and gatifloxacin combination. A partial synergism interaction between meropenem and polymyxin B was observed for 80% of the A. baumannii strains. In contrast, this combination showed an indifferent effect for 80% of the P. aeruginosa strains tested. The combination of meropenem and gatifloxacin showed synergism only for two strains of A. baumannii, and partial synergism and additive effect for seven strains and indifference for four strains of both species. For the strains of P. aeruginosa, the double combination of polymyxin B and gatifloxacin and the triple combination of meropenem, polymyxin B and gatifloxacin were indifferent for the majority of the strains tested, that is, 90 and 80% respectively.
authors.affiliation: Department of Clinical Analyses, Universidade Estadual de Maringá, Maringá, PR, Brazil.
authors.forename: K C
authors.initials: KC
authors.lastname: Guelfi
authors.forename: M C B
authors.initials: MC
authors.lastname: Tognim
authors.forename: C L
authors.initials: CL
authors.lastname: Cardoso
authors.forename: A C
authors.initials: AC
authors.lastname: Gales
authors.forename: F E
authors.initials: FE
authors.lastname: Carrara-Marrone
authors.forename: L B
authors.initials: LB
authors.lastname: Garcia
mesh_terms: D040981:Acinetobacter baumannii / Q000187:drug effects*; D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000494:pharmacology*; D004357:Drug Synergism; D024841:Fluoroquinolones / Q000008:administration & dosage / Q000494:pharmacology*; D000077734:Gatifloxacin; D000077731:Meropenem; D008826:Microbial Sensitivity Tests; D011112:Polymyxin B / Q000008:administration & dosage / Q000494:pharmacology*; D011550:Pseudomonas aeruginosa / Q000187:drug effects*; D013845:Thienamycins / Q000008:administration & dosage / Q000494:pharmacology*
chemical_list: D000900:Anti-Bacterial Agents; D024841:Fluoroquinolones; D013845:Thienamycins; D000077731:Meropenem; D011112:Polymyxin B; D000077734:Gatifloxacin