title: Overcoming an Extremely Drug Resistant (XDR) Pathogen: Avibactam Restores Susceptibility to Ceftazidime for Burkholderia cepacia Complex Isolates from Cystic Fibrosis Patients.
abstract: Burkholderia multivorans is a significant health threat to persons with cystic fibrosis (CF). Infections are difficult to treat as this pathogen is inherently resistant to multiple antibiotics. Susceptibility testing of isolates obtained from CF respiratory cultures revealed that single agents selected from different antibiotic classes were unable to inhibit growth. However, all isolates were found to be susceptible to ceftazidime when combined with the novel non-β-lactam β-lactamase inhibitor, avibactam (all minimum inhibitor concentrations (MICs) were ≤8 mg/L of ceftazidime and 4 mg/L of avibactam). Furthermore, a major β-lactam resistance determinant expressed in B. multivorans, the class A carbapenemase, PenA was readily inhibited by avibactam with a high k2/K of (2 ± 1) × 106μM-1s-1and a slow koffof (2 ± 1) × 10-3s-1. Mass spectrometry revealed that avibactam formed a stable complex with PenA for up to 24 h and that avibactam recyclized off of PenA, re-forming the active compound. Crystallographic analysis of PenA-avibactam revealed several interactions that stabilized the acyl-enzyme complex. The deacylation water molecule possessed decreased nucleophilicity, preventing decarbamylation. In addition, the hydrogen-bonding interactions with Lys-73 were suggestive of a protonated state. Thus, Lys-73 was unlikely to abstract a proton from Ser-130 to initiate recyclization. Using Galleria mellonella larvae as a model for infection, ceftazidime-avibactam was shown to significantly (p < 0.001) improve survival of larvae infected with B. multivorans. To further support the translational impact, the ceftazidime-avibactam combination was evaluated using susceptibility testing against other strains of Burkholderia spp. that commonly infect individuals with CF, and 90% of the isolates were susceptible to the combination. In summary, ceftazidime-avibactam may serve as a preferred therapy for people that have CF and develop Burkholderia spp. infections and should be considered for clinical trials.
authors.affiliation: Research Service, Louis Stokes Cleveland Department of Veterans Affairs , 10701 East Boulevard, Cleveland, Ohio 44106, United States.|Department of Medicine, Case Western Reserve University , 10900 Euclid Avenue, Cleveland, Ohio 44106, United States.|Department of Biochemistry, Case Western Reserve University , 10900 Euclid Avenue, Cleveland, Ohio 44106, United States.
authors.forename: Krisztina M
authors.initials: KM
authors.lastname: Papp-Wallace
authors.affiliation: Research Service, Louis Stokes Cleveland Department of Veterans Affairs , 10701 East Boulevard, Cleveland, Ohio 44106, United States.
authors.forename: Scott A
authors.initials: SA
authors.lastname: Becka
authors.affiliation: Research Service, Louis Stokes Cleveland Department of Veterans Affairs , 10701 East Boulevard, Cleveland, Ohio 44106, United States.
authors.forename: Elise T
authors.initials: ET
authors.lastname: Zeiser
authors.affiliation: Department of Pharmaceutical Sciences, Josai International University , 1 Gumyo, Togane City, Chiba, 283-8555 Japan.
authors.forename: Nozomi
authors.initials: N
authors.lastname: Ohuchi
authors.affiliation: Research Service, Louis Stokes Cleveland Department of Veterans Affairs , 10701 East Boulevard, Cleveland, Ohio 44106, United States.|Department of Biochemistry, Case Western Reserve University , 10900 Euclid Avenue, Cleveland, Ohio 44106, United States.
authors.forename: Maria F
authors.initials: MF
authors.lastname: Mojica
authors.affiliation: Research Service, Louis Stokes Cleveland Department of Veterans Affairs , 10701 East Boulevard, Cleveland, Ohio 44106, United States.
authors.forename: Julian A
authors.initials: JA
authors.lastname: Gatta
authors.affiliation: Department of Health Sciences, University of Milan , Via di Rudinì 8, 20142 Milan, Italy.
authors.forename: Monica
authors.initials: M
authors.lastname: Falleni
authors.affiliation: Department of Health Sciences, University of Milan , Via di Rudinì 8, 20142 Milan, Italy.
authors.forename: Delfina
authors.initials: D
authors.lastname: Tosi
authors.affiliation: Department of Health Sciences, University of Milan , Via di Rudinì 8, 20142 Milan, Italy.
authors.forename: Elisa
authors.initials: E
authors.lastname: Borghi
authors.affiliation: Research Service, Louis Stokes Cleveland Department of Veterans Affairs , 10701 East Boulevard, Cleveland, Ohio 44106, United States.|Department of Molecular Biology and Microbiology, Case Western Reserve University , 10900 Euclid Avenue, Cleveland, Ohio 44106, United States.
authors.forename: Marisa L
authors.initials: ML
authors.lastname: Winkler
authors.affiliation: Research Service, Louis Stokes Cleveland Department of Veterans Affairs , 10701 East Boulevard, Cleveland, Ohio 44106, United States.
authors.forename: Brigid M
authors.initials: BM
authors.lastname: Wilson
authors.affiliation: Department of Pediatrics and Communicable Disease, University of Michigan Medical School , 4810 Jackson Road, Ann Arbor, Michigan 48103, United States.
authors.forename: John J
authors.initials: JJ
authors.lastname: LiPuma
authors.affiliation: Department of Pharmaceutical Sciences, Josai International University , 1 Gumyo, Togane City, Chiba, 283-8555 Japan.
authors.forename: Michiyoshi
authors.initials: M
authors.lastname: Nukaga
authors.affiliation: Research Service, Louis Stokes Cleveland Department of Veterans Affairs , 10701 East Boulevard, Cleveland, Ohio 44106, United States.|Department of Medicine, Case Western Reserve University , 10900 Euclid Avenue, Cleveland, Ohio 44106, United States.|Department of Molecular Biology and Microbiology, Case Western Reserve University , 10900 Euclid Avenue, Cleveland, Ohio 44106, United States.|Department of Pharmacology, Case Western Reserve University , 10900 Euclid Avenue, Cleveland, Ohio 44106, United States.|Department of Biochemistry, Case Western Reserve University , 10900 Euclid Avenue, Cleveland, Ohio 44106, United States.
authors.forename: Robert A
authors.identifier: 0000-0002-3299-894X
authors.initials: RA
authors.lastname: Bonomo
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D053961:Azabicyclo Compounds / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism; D019121:Burkholderia Infections / Q000382:microbiology*; D042602:Burkholderia cepacia complex / Q000187:drug effects* / Q000201:enzymology / Q000254:growth & development / Q000302:isolation & purification; D002442:Ceftazidime / Q000494:pharmacology*; D003550:Cystic Fibrosis / Q000382:microbiology; D004357:Drug Synergism; D004359:Drug Therapy, Combination; D006801:Humans; D006860:Hydrogen Bonding; D007814:Larva / Q000187:drug effects / Q000382:microbiology; D008826:Microbial Sensitivity Tests; D009036:Moths / Q000187:drug effects / Q000382:microbiology; D009894:Opportunistic Infections / Q000382:microbiology; D011485:Protein Binding; D011522:Protons; D018440:beta-Lactam Resistance / Q000187:drug effects; D001618:beta-Lactamases / Q000378:metabolism
chemical_list: D000900:Anti-Bacterial Agents; D053961:Azabicyclo Compounds; D001426:Bacterial Proteins; D011522:Protons; C543519:avibactam; D002442:Ceftazidime; D001618:beta-Lactamases; C063912:carbapenemase
keywords: Burkholderia; avibactam; ceftazidime; cystic fibrosis; β-lactamase; β-lactamase inhibitor