Comparative Evaluation of the <i>In Vitro</i> Activities of WCK 5222 (Cefepime-Zidebactam) and Combination Antibiotic Therapies against Carbapenem-Resistant <i>Pseudomonas aeruginosa</i>

Abstract

The <i>in vitro</i> activity of WCK 5222 (cefepime-zidebactam) was compared to that of several available combination therapies among 30 clinical carbapenem-resistant <i>Pseudomonas aeruginosa</i> (CRP) strains using gradient diffusion strips. The combinations included nonsusceptible β-lactams (cefepime, ceftolozane-tazobactam, and meropenem) with amikacin and fosfomycin. WCK 5222 MICs ranged from 2 to 32 mg/liter, and 97% were ≤16 mg/liter, while 105/146 (72%) combinations demonstrated inhibition below established susceptibility breakpoints. WCK 5222 monotherapy may be preferred over the combinations assessed for CRP infections.