First Report of blaNDM-1 Bearing IncX3 Plasmid in Clinically Isolated ST11 Klebsiella pneumoniae from Pakistan

Abstract

The New Delhi Metallo-β-lactamase (NDM) is among the most threatening forms of carbapenemases produced by <i>K. pneumoniae</i>, well-known to cause severe worldwide infections. The molecular epidemiology of <i>bla</i>_NDM-1-harboring <i>K. pneumoniae</i> is not well elucidated in Pakistan. Herein, we aim to determine the antibiotics-resistance profile, genes type, molecular type, and plasmid analysis of 125 clinically isolated <i>K. pneumoniae</i> strains from urine samples during July 2018 to January 2019 in Pakistan. A total of 34 (27.2%) <i>K. pneumoniae</i> isolates were carbapenemases producers, and 23 (18.4%) harbored the <i>bla</i>_NDM-1 gene. The other carbapenemases encoding genes, i.e., <i>bla</i>_IMP-1 (7.2%), <i>bla</i>_VIM-1 (3.2%), and <i>bla</i>_OXA-48 (2.4%) were also detected. The Multi Locus Sequence Typing (MLST) results revealed that all <i>bla</i>_NDM-1-harboring isolates were ST11. The other sequence types detected were ST1, ST37, and ST105. The cluster analysis of Xbal Pulsed Field Gel Electrophoresis (PFGE) revealed variation amongst the clusters of the identical sequence type isolates. The <i>bla</i>_NDM-1 gene in all of the isolates was located on a 45-kb IncX3 plasmid, successfully transconjugated. For the first time, <i>bla</i>_NDM-1-bearing IncX3 plasmids were identified from Pakistan, and this might be a new primary vehicle for disseminating <i>bla</i>_NDM-1 in Enterobacteriaceae as it has a high rate of transferability.