Genetic characterization of Klebsiella pneumoniae carbapenemase-producing Klebsiella pneumoniae isolates with different susceptibility to ceftazidime/avibactam in patients with blood-stream infections

The dissemination of multi-drug resistant (MDR) Gram-negative bacteria (GNB) poses a serious threat to global health. Novel β-lactams/β-lactamase inhibitor combinations (n-βL-βLICs) represent the mainstay to contain MDR-GNB-related mortality. In 2015, ceftazidime/avibactam (C/A) was approved for intra-abdominal and urinary infections, hospital-acquired pneumonia and GNB infections with limited treatment options. Its spectrum includes Enterobacterales and P. aeruginosa, overcoming resistance due to Ambler class-A, class-C and some class-D β-lactamases.