Dissemination of Genetically Diverse NDM-1, -5, -7 Producing-Gram-Negative Pathogens Isolated from Pediatric Patients in Pakistan

Abstract

<b>Aim:</b> To determine the prevalence of New Delhi metallo-β-lactamase (NDM)-producing Gram-negative pathogens isolated from children's samples. <b>Materials & methods:</b> Carbapenem-resistant clinical isolates (n = 117) were confirmed by VITEK^® 2 compact system, matrix-assisted laser desorption ionization-time of flight and multilocus sequence typing. MIC (μg/ml) of various antibiotics was determined by VITEK 2 compact system. Molecular characterization of the isolates was performed by PCR, DNA sequencing, PFGE and DNA hybridization. <b>Results:</b> Out of 117 carbapenemase producers, 37 (31.6%) and 29 (24.7%) were <i>Klebsiella pneumoniae</i> and <i>Acinetobacter baumannii</i>, respectively. 72 (61.5%) isolates were NDM positive and among these 60, 9 and 3 were NDM-1, -5 and -7, respectively. Majority of the NDM-producing <i>K. pneumoniae</i> belonged to ST11 and ST273 while most of the <i>Escherichia coli</i> belonged to ST405 and ST101. <i>bla</i>_NDM were mainly located on 150kb plasmids. MIC displayed high resistance against β-lactams drugs including carbapenems, and the most sensitive drugs were tigecycline and colistin. <b>Conclusion:</b> Dissemination of <i>bla</i>_NDM-producing pathogens, particularly in children clinical settings, is a matter of great public health concern.