Emergence of Resistance to Ceftazidime-Avibactam in a Pseudomonas aeruginosa Isolate Producing Derepressed bla_PDC in a Hollow-Fiber Infection Model.

ABSTRACT: Ceftazidime (CAZ)-avibactam (AVI) is a β-lactam/β-lactamase inhibitor combination with activity against type A and type C β-lactamases. Resistance emergence has been seen, with multiple mechanisms accounting for the resistance. We performed four experiments in the dynamic hollow-fiber infection model, delineating the linkage between drug exposure and both the rate of bacterial kill and resistance emergence by all mechanisms. The Pseudomonas aeruginosa isolate had MICs of 1.0 mg/liter (CAZ) and 4 mg/liter (AVI). We demonstrated that the time at ≥4.0 mg/liter AVI was linked to the rate of bacterial kill. Linkage to resistance emergence/suppression was more complex. In one experiment in which CAZ and AVI administration was intermittent and continuous, respectively, and in which AVI was

SUBMITTER: Drusano GL 

PROVIDER: S-EPMC8316140 | biostudies-literature | 2021 May

REPOSITORIES: biostudies-literature