title: Comparative activities of colistin, rifampicin, imipenem and sulbactam/ampicillin alone or in combination against epidemic multidrug-resistant Acinetobacter baumannii isolates producing OXA-58 carbapenemases.
abstract: This study evaluated the activity of colistin, rifampicin, imipenem and sulbactam/ampicillin alone or in combination against nine epidemic multidrug-resistant Acinetobacter baumannii isolates producing OXA-58 carbapenemase in Naples, Italy. The isolates were susceptible to colistin but differed in their resistance to imipenem and rifampicin. Time-kill studies showed a bactericidal effect for colistin but not for imipenem, rifampicin or sulbactam/ampicillin used as single agents. Synergism was observed with combinations of rifampicin+imipenem or sulbactam/ampicillin for all isolates and with colistin+rifampicin for isolates showing higher minimum inhibitory concentrations for rifampicin. Combined use of the antimicrobials tested may provide good therapeutic options for OXA-58 carbapenemase-producing A. baumannii infections.
authors.affiliation: Internal Medicine, Second University of Naples, Naples, Italy.
authors.forename: Marie-Francoise
authors.initials: MF
authors.lastname: Tripodi
authors.forename: Emanuele
authors.initials: E
authors.lastname: Durante-Mangoni
authors.forename: Rosaria
authors.initials: R
authors.lastname: Fortunato
authors.forename: Riccardo
authors.initials: R
authors.lastname: Utili
authors.forename: Raffaele
authors.initials: R
authors.lastname: Zarrilli
mesh_terms: D000151:Acinetobacter Infections / Q000453:epidemiology* / Q000382:microbiology; D040981:Acinetobacter baumannii / Q000187:drug effects* / Q000201:enzymology / Q000235:genetics / Q000302:isolation & purification; D000667:Ampicillin / Q000494:pharmacology; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000096:biosynthesis*; D015780:Carbapenems / Q000494:pharmacology; D003091:Colistin / Q000494:pharmacology; D004196:Disease Outbreaks; D024901:Drug Resistance, Multiple, Bacterial; D004357:Drug Synergism; D016521:Electrophoresis, Gel, Pulsed-Field; D006801:Humans; D015378:Imipenem / Q000494:pharmacology; D007558:Italy / Q000453:epidemiology; D008826:Microbial Sensitivity Tests; D012293:Rifampin / Q000494:pharmacology; D013407:Sulbactam; D001618:beta-Lactamases / Q000096:biosynthesis*
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D015780:Carbapenems; D015378:Imipenem; D000667:Ampicillin; D001618:beta-Lactamases; C063912:carbapenemase; D013407:Sulbactam; D012293:Rifampin; D003091:Colistin