Prevalence and molecular characterization of Enterobacteriaceae producing NDM-1 carbapenemase at a military hospital in Pakistan and evaluation of two chromogenic media

Diagn Microbiol Infect Dis. 2013 Feb;75(2):187-91. doi: 10.1016/j.diagmicrobio.2012.11.006. Epub 2012 Dec 14.

Abstract

The aim of this study was to assess the frequency and genotypic diversity of carbapenemase-producing Enterobacteriaceae (CPE) in stool samples from patients attending a military hospital in Pakistan. Further aims included the identification of factors that might predispose to faecal carriage and evaluation of 2 chromogenic culture media: Brilliance CRE and chromID CARBA. Of 175 patients, 32 (18.3%) had faecal carriage of CPE and all produced NDM-1 carbapenemase. All of these 32 patients were detected using chromID CARBA compared with 20 patients (62.5%) detected using Brilliance CRE (P = 0.0015). Duration of hospitalization and treatment with co-amoxyclav were statistically associated with a higher likelihood of carriage of CPE (P ≤ 0.05). The majority of NDM-1-producing Enterobacteriaceae co-produced CTX-M-1 group extended spectrum β-lactamase, and one third produced armA-type methylase. NDM-1 carbapenemase was most commonly found amongst commensal types of Escherichia coli, especially phylogenetic group B1.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Child
  • Culture Media
  • Enterobacteriaceae / drug effects
  • Enterobacteriaceae / enzymology*
  • Enterobacteriaceae / genetics*
  • Enterobacteriaceae / isolation & purification
  • Enterobacteriaceae Infections / microbiology*
  • Feces / microbiology
  • Genes, Bacterial
  • Hospitals, Military
  • Humans
  • Length of Stay
  • Male
  • Microbial Sensitivity Tests
  • Middle Aged
  • Phylogeny
  • Prevalence
  • beta-Lactam Resistance
  • beta-Lactamases / biosynthesis*
  • beta-Lactamases / genetics

Substances

  • Culture Media
  • beta-Lactamases
  • beta-lactamase NDM-1