Dissemination of genetically diverse NDM-1, -5, -7 producing-Gram-negative pathogens isolated from pediatric patients in Pakistan.

Abstract

Aim: To determine the prevalence of New Delhi metallo-β-lactamase (NDM)-producing Gram-negative pathogens isolated from children's samples. Materials & methods: 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 VITEK2 compact system. Molecular characterization of the isolates was performed by PCR, DNA sequencing,PFGE and DNA hybridization. Results: Out of 117 carbapenemase producers, 37 (31.6%) and 29 (24.7%) were Klebsiella pneumoniae and Acinetobacter baumannii, respectively. 72 (61.5%) isolates were NDM positive and among these60, 9 and 3 were NDM-1, -5 and -7, respectively. Majority of the NDM-producing K. pneumoniaebelonged to ST11and ST273while most of theEscherichiacoli belonged to ST405 and ST101. blaNDM 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. Conclusion: Dissemination of blaNDM-producing pathogens, particularly in children clinical settings, is a matter of great public health concern.