Emergence of Ceftazidime-Avibactam resistant KPC-producing K. pneumoniae (KPC-Kp) during ceftazidime-avibactam-based antimicrobial treatment.. Whole-Genome Sequencing of Ceftazidime-Avibactam resistant KPC-producing Klebsiella pneumoniae strains

Here we describe a case of ceftazidime-avibactam (CAZ-AVI) resistant K. pneumoniae strains emerged during a treatment of Bloodstream infection (BSI) due to KPC-producing K. pneumoniae. The patient was initially treated with CAZ-AVI-based antimicrobial regimen for a Bloodstream infection due to CAZ-AVI-susceptible KPC-Kp strain. After two weeks of treatment, two CAZ-AVI -resistant KPC-producing K. pneumoniae strains were isolated from blood and Broncho-Alveolar Lavage. Whole-Genome Sequencing (WGS) was performed both on ceftazidime-avibactam -susceptible and -resistant strains in order to identify the mechanisms of CAZ-AVI resistance. WGS was performed by using an Illumina MiSeq sequencer with a 2x250 pair-end run. Library preparation was performed using an Illumina Nextera XT kit.