Characterization of a Plasmid-Encoded Resistance-Nodulation-Division Efflux Pump in <i>Klebsiella pneumoniae</i> and <i>Klebsiella quasipneumoniae</i> from Patients in China

Abstract

Two multidrug-resistant (MDR) <i>mcr-1</i>-harboring <i>Klebsiella pneumoniae</i> isolates from patients with urinary tract infections and one MDR <i>Klebsiella quasipneumoniae</i> isolate from a patient with bloodstream infection were identified to carry <i>tmexCD1-toprJ1</i> The addition of the efflux pump inhibitor reduced the tigecycline MIC against all three isolates by 8- to 16-fold. pKQBSI104-1 was transferred from <i>K. quasipneumoniae</i> to <i>Escherichia coli</i> J53 via conjugation. The <i>tmexCD1-toprJ1</i>-carrying plasmids pKP15ZE495-1 (102,569 bp) and pKQBSI104-1 (121,996 bp) were completely sequenced and analyzed.