Evaluation of in vitro pharmacodynamic drug interactions of ceftazidime-avibactam with tigecycline in ESBL- and carbapenemase producing Escherichia coli and Klebsiella pneumoniae.

Background: Combination therapy offers a promising option to enhance efficacy and prevent resistance. A comprehensive and quantitative assessment of the last-resort combination of ceftazidime/avibactam and tigecycline is not available.

Objective: This study systematically investigated the pharmacodynamic interaction between ceftazidime/avibactam and tigecycline in clinical and isogenic Escherichia coli and Klebsiella pneumoniae strains harbouring genes that encode various carbapenemases or ESBLs.