Targeting Multidrug-Resistant spp.: Sulbactam and the Diazabicyclooctenone β-Lactamase Inhibitor ETX2514 as a Novel Therapeutic Agent.
Melissa D Barnes, Vijay Kumar, Christopher R Bethel, Samir H Moussa, John O'Donnell, Joseph D Rutter, Caryn E Good, Kristine M Hujer, Andrea M Hujer, Steve H Marshall, Barry N Kreiswirth, Sandra S Richter, Philip N Rather, Michael R Jacobs, Krisztina M Papp-Wallace, Focco van den Akker, Robert A Bonomo
Author Information
Melissa D Barnes: Louis Stokes Cleveland Veterans Affairs Medical Center Research Service, Cleveland, Ohio, USA.
Vijay Kumar: Department of Biochemistry, Case Western Reserve University, Cleveland, Ohio, USA. ORCID
Christopher R Bethel: Louis Stokes Cleveland Veterans Affairs Medical Center Research Service, Cleveland, Ohio, USA.
Samir H Moussa: Entasis Therapeutics, Waltham, Massachusetts, USA.
John O'Donnell: Entasis Therapeutics, Waltham, Massachusetts, USA.
Joseph D Rutter: Louis Stokes Cleveland Veterans Affairs Medical Center Research Service, Cleveland, Ohio, USA.
Caryn E Good: Department of Pathology, University Hospitals, Cleveland Medical Center, Cleveland, Ohio, USA.
Kristine M Hujer: Louis Stokes Cleveland Veterans Affairs Medical Center Research Service, Cleveland, Ohio, USA.
Andrea M Hujer: Louis Stokes Cleveland Veterans Affairs Medical Center Research Service, Cleveland, Ohio, USA.
Steve H Marshall: Louis Stokes Cleveland Veterans Affairs Medical Center Research Service, Cleveland, Ohio, USA.
Barry N Kreiswirth: Public Health Research Institute Tuberculosis Center, New Jersey Medical School, Rutgers University, Newark, New Jersey, USA.
Sandra S Richter: Cleveland Clinic Foundation, Cleveland, Ohio, USA.
Philip N Rather: Department of Microbiology and Immunology, Emory University School of Medicine, Atlanta, Georgia, USA.
Michael R Jacobs: Department of Medicine, Case Western Reserve University, Cleveland, Ohio, USA.
Krisztina M Papp-Wallace: Louis Stokes Cleveland Veterans Affairs Medical Center Research Service, Cleveland, Ohio, USA. ORCID
Focco van den Akker: Department of Biochemistry, Case Western Reserve University, Cleveland, Ohio, USA fxv5@case.edu robert.bonomo@va.gov.
Robert A Bonomo: Louis Stokes Cleveland Veterans Affairs Medical Center Research Service, Cleveland, Ohio, USA fxv5@case.edu robert.bonomo@va.gov.
Multidrug-resistant (MDR) spp. poses a significant therapeutic challenge in part due to the presence of chromosomally encoded β-lactamases, including class C -derived cephalosporinases (ADC) and class D oxacillinases (OXA), as well as plasmid-mediated class A β-lactamases. Importantly, OXA-like β-lactamases represent a gap in the spectrum of inhibition by recently approved β-lactamase inhibitors such as avibactam and vaborbactam. ETX2514 is a novel, rationally designed, diazabicyclooctenone inhibitor that effectively targets class A, C, and D β-lactamases. We show that addition of ETX2514 significantly increased the susceptibility of clinical isolates to sulbactam. AdeB and AdeJ were identified to be key efflux constituents for ETX2514 in The combination of sulbactam and ETX2514 was efficacious against carrying , , , and in a neutropenic murine thigh infection model. We also show that, , ETX2514 inhibited ADC-7 (/ 1.0 ± 0.1 × 10 M s) and OXA-58 (/ 2.5 ± 0.3 × 10 M s). Cocrystallization of ETX2514 with OXA-24/40 revealed hydrogen bonding interactions between ETX2514 and residues R261, S219, and S128 of OXA-24/40 in addition to a chloride ion occupied in the active site. Further, the C3 methyl group of ETX2514 shifts the position of M223. In conclusion, the sulbactam-ETX2514 combination possesses a broadened inhibitory range to include class D β-lactamases as well as class A and C β-lactamases and is a promising therapeutic candidate for infections caused by MDR spp. The number and diversity of β-lactamases are steadily increasing. The emergence of β-lactamases that hydrolyze carbapenems poses a significant threat to our antibiotic armamentarium. The explosion of OXA enzymes that are carbapenem hydrolyzers is a major challenge (carbapenem-hydrolyzing class D [CHD]). An urgent need exists to discover β-lactamase inhibitors with class D activity. The sulbactam-ETX2514 combination demonstrates the potential to become a treatment regimen of choice for spp. producing class D β-lactamases.
