title: In vitro responses of Acinetobacter baumannii to two- and three-drug combinations following exposure to colistin and doripenem.
abstract: We compared in vitro killing of colistin, doripenem, and sulbactam by time-kill methods against Acinetobacter baumannii isolates collected from patients before and after colistin-doripenem treatment (initial and recurrent isolates, respectively). Colistin-doripenem bactericidal activity against recurrent isolates was attenuated (mean log10 kill, -5.74 versus -2.88; P = 0.01) but was restored by adding sulbactam. Doripenem MICs rather than colistin MICs correlated with the activity of colistin-doripenem. Among colistin-resistant isolates, colistin-doripenem-sulbactam combinations achieved greater killing than colistin-doripenem alone (-5.65 versus -2.43; P = 0.04).
authors.affiliation: Antibiotic Management Program, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA.
authors.forename: Louise M
authors.initials: LM
authors.lastname: Oleksiuk
authors.forename: M Hong
authors.initials: MH
authors.lastname: Nguyen
authors.forename: Ellen G
authors.initials: EG
authors.lastname: Press
authors.forename: Cassaundra L
authors.initials: CL
authors.lastname: Updike
authors.forename: Jessica A
authors.initials: JA
authors.lastname: O'Hara
authors.forename: Yohei
authors.initials: Y
authors.lastname: Doi
authors.forename: Cornelius J
authors.initials: CJ
authors.lastname: Clancy
authors.forename: Ryan K
authors.initials: RK
authors.lastname: Shields
mesh_terms: D000151:Acinetobacter Infections / Q000188:drug therapy* / Q000382:microbiology; D040981:Acinetobacter baumannii / Q000187:drug effects* / Q000235:genetics / Q000254:growth & development / Q000302:isolation & purification; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D015780:Carbapenems / Q000494:pharmacology*; D003091:Colistin / Q000494:pharmacology*; D000077726:Doripenem; D004334:Drug Administration Schedule; D004338:Drug Combinations; D024881:Drug Resistance, Bacterial / Q000235:genetics; D016521:Electrophoresis, Gel, Pulsed-Field; D006801:Humans; D013407:Sulbactam / Q000494:pharmacology*
chemical_list: D000900:Anti-Bacterial Agents; D015780:Carbapenems; D004338:Drug Combinations; D000077726:Doripenem; D013407:Sulbactam; D003091:Colistin