Ceftazidime-Avibactam Resistance Associated with Increased <i>bla</i> <sub>KPC-3</sub> Gene Copy Number Mediated by pKpQIL Plasmid Derivatives in Sequence Type 258 <i>Klebsiella pneumoniae</i>
Marco Coppi, Vincenzo Di Pilato, Francesco Monaco, Tommaso Giani, Pier Giulio Conaldi, Gian María Rossolini
Abstract
This study reports on the characterization of two ceftazidime-avibactam (CZA)-resistant KPC-producing Klebsiella pneumoniae strains (KP-14159 and KP-8788) sequentially isolated from infections occurred in a patient never treated with CZA. Whole-genome sequencing characterization using a combined short- and long-read sequencing approach showed that both isolates belonged to the same ST258 strain, had altered outer membrane porins (a truncated OmpK35 and an Asp137Thr138 duplication in the L3 loop of OmpK36), and carried novel pKpQIL plasmid derivatives (pIT-14159 and pIT-8788, respectively) harboring two copies of the Tn 4401a KPC-3-encoding transposon.