Change in Klebsiella pneumoniae susceptibility profile after the arrival of ceftazidime-avibactam in an Argentinean intensive care unit: a new ecological landscape

Ceftazidime-avibactam (CZA) is a good option for Gram-negative bacilli infections that produce carbapenemase Classes A (especially blaKPC) and D (blaOXA). However, it is unknown whether it would have an impact on metallo-β-lactamases (blaMBL) selection. The aim of the study was to compare carbapenem and CZA Klebsiella pneumoniae (KPN) susceptibility profiles for a period of two years following the introduction of CZA. The study was conducted in a 36-bed adult ICU of a tertiary hospital in Buenos Aires, Argentina. Antimicrobial consumption was expressed as days of treatment per 100 patients-day (DOT). A total of 123 KPN strains in the first year and 172 in the second year were analyzed. An alarming decrease in carbapenem susceptibility was detected in the second year (OR 0.5 [0.3-0.8] p