In vitro susceptibility of nonfermenting Gram-negative rods to meropenem–vaborbactam and delafloxacin

Abstract

Aim: Meropenem–vaborbactam and delafloxacin activities were not assessed against Achromobacter spp. ( Achr), Burkholderia cepacia complex ( Bcc) and Stenotrophomonas maltophilia ( Smal). Methodology: A total of 106 Achr, 57 Bcc and 100 Smal were tested with gradient diffusion test of meropenem–vaborbactam, delafloxacin and comparators. Results: Meropenem–vaborbactam MIC50 were 4 μg/ml for Achr, 1 μg/ml for B. cepacia, 2 μg/ml for B. cenocepacia and B. multivorans, and 32 μg/ml for Smal. Delafloxacin MIC50 were 4 μg/ml for Achr, 0.25 μg/ml for B. cepacia and B. multivorans, 2 μg/ml for B. cenocepacia, and 0.5 μg/m for Smal. meropenem–vaborbactam MICs were fourfold lower than meropenem for 28.3% Achr, 77.2% B. cepacia, 53.8% B. cenocepacia and 77.2% B. multivorans. Conclusion: Meropenem–vaborbactam and delafloxacin are in vitro active against Bcc and Achr.