title: Evaluation of the In Vitro Activity of Ceftazidime-Avibactam and Ceftolozane-Tazobactam against Meropenem-Resistant Pseudomonas aeruginosa Isolates.
abstract: We compared ceftazidime-avibactam, ceftolozane-tazobactam, ceftazidime, cefepime, and piperacillin-tazobactam MICs for 38 meropenem-resistant Pseudomonas aeruginosa isolates. No isolates harbored carbapenemases; 74% were oprD mutants. Ceftazidime-avibactam and ceftolozane-tazobactam were active against 92% of the isolates, including 80% that were resistant to all three β-lactams. Forty-three percent of ceftazidime-avibactam-susceptible isolates and 6% of ceftolozane-tazobactam-susceptible isolates exhibited MICs at the respective breakpoints. Ceftolozane-tazobactam and ceftazidime-avibactam are therapeutic options for meropenem-resistant P. aeruginosa infections that should be used judiciously to preserve activity.
authors.affiliation: Department of Pharmacy and Therapeutics, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.
authors.forename: Deanna J
authors.initials: DJ
authors.lastname: Buehrle
authors.affiliation: Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA XDR Pathogen Laboratory, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA.
authors.forename: Ryan K
authors.initials: RK
authors.lastname: Shields
authors.affiliation: Rutgers University-New Jersey Medical School, Newark, New Jersey, USA.
authors.forename: Liang
authors.initials: L
authors.lastname: Chen
authors.affiliation: XDR Pathogen Laboratory, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA.
authors.forename: Binghua
authors.initials: B
authors.lastname: Hao
authors.affiliation: Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.
authors.forename: Ellen G
authors.initials: EG
authors.lastname: Press
authors.affiliation: Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.
authors.forename: Ammar
authors.initials: A
authors.lastname: Alkrouk
authors.affiliation: Department of Pharmacy and Therapeutics, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.
authors.forename: Brian A
authors.initials: BA
authors.lastname: Potoski
authors.affiliation: Rutgers University-New Jersey Medical School, Newark, New Jersey, USA.
authors.forename: Barry N
authors.initials: BN
authors.lastname: Kreiswirth
authors.affiliation: Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA XDR Pathogen Laboratory, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA VA Pittsburgh Healthcare System, Pittsburgh, Pennsylvania, USA cjc76@pitt.edu.
authors.forename: Cornelius J
authors.initials: CJ
authors.lastname: Clancy
authors.affiliation: Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA XDR Pathogen Laboratory, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA.
authors.forename: M Hong
authors.initials: MH
authors.lastname: Nguyen
mesh_terms: D053961:Azabicyclo Compounds / Q000494:pharmacology*; D002442:Ceftazidime / Q000494:pharmacology*; D002511:Cephalosporins / Q000494:pharmacology*; D004338:Drug Combinations; D024881:Drug Resistance, Bacterial / Q000235:genetics; D000077731:Meropenem; D008826:Microbial Sensitivity Tests; D010397:Penicillanic Acid / Q000031:analogs & derivatives* / Q000494:pharmacology; D011550:Pseudomonas aeruginosa / Q000187:drug effects* / Q000201:enzymology; D000078142:Tazobactam; D013845:Thienamycins / Q000494:pharmacology*
chemical_list: D053961:Azabicyclo Compounds; D002511:Cephalosporins; D004338:Drug Combinations; D013845:Thienamycins; C000595613:avibactam, ceftazidime drug combination; C519491:ceftolozane; D010397:Penicillanic Acid; D002442:Ceftazidime; D000077731:Meropenem; D000078142:Tazobactam