Prevalence and characterization of multidrug-resistant and extended-spectrum beta-lactamase-producing Escherichia coli from pediatric wards of a Malaysian hospital

Microb Drug Resist. 2012 Aug;18(4):408-16. doi: 10.1089/mdr.2011.0222. Epub 2012 Mar 6.

Abstract

The emergence of Escherichia coli resistant to extended-spectrum cephalosporins (ESCs) is of concern as ESC is often used to treat infections by Gram-negative bacteria. One-hundred and ten E. coli strains isolated in 2009-2010 from children warded in a Malaysian tertiary hospital were analyzed for their antibiograms, carriage of extended-spectrum beta-lactamase (ESBL) and AmpC genes, possible inclusion of the beta-lactamase genes on an integron platform, and their genetic relatedness. All E. coli strains were sensitive to carbapenems. About 46% of strains were multidrug resistant (MDR; i.e., resistant to ≥3 antibiotic classes) and almost half (45%) were nonsusceptible to ESCs. Among the MDR strains, high resistance rates were observed for ampicillin (98%), tetracycline (75%), and trimethoprim/sulfamethoxazole (73%). Out of 110 strains, bla(TEM-1) (49.1%), bla(CTX-M) (11.8%), and bla(CMY-2) (6.4%) were detected. Twenty-one strains were ESBL producers. CTX-M-15 was the predominant CTX-M variant found and this is the first report of a CTX-M-27-producing E. coli strain from Malaysia. Majority (3.1%) of the strains harbored class 1 integron-encoded integrases with a predominance of aadA and dfr genes within the integron variable region. No gene cassette encoding ESBL genes was found and integrons were not significantly associated with ESBL or non-ESBL producers. Possible clonal expansion was observed for few CTX-M-15-positive strains but the O25-ST131 E. coli clone known to harbor CTX-M-15 was not detected while CMY-2-positive strains were genetically diverse.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anti-Bacterial Agents / pharmacology
  • Bacterial Proteins / genetics*
  • Carbapenems / pharmacology
  • Cephalosporins / pharmacology
  • Child, Preschool
  • Drug Resistance, Multiple, Bacterial / drug effects
  • Drug Resistance, Multiple, Bacterial / genetics*
  • Electrophoresis, Gel, Pulsed-Field
  • Escherichia coli / drug effects
  • Escherichia coli / genetics*
  • Escherichia coli / isolation & purification
  • Escherichia coli Infections / drug therapy
  • Escherichia coli Infections / epidemiology
  • Escherichia coli Infections / microbiology*
  • Humans
  • Infant
  • Integrases / genetics*
  • Malaysia / epidemiology
  • Microbial Sensitivity Tests
  • Phylogeny
  • Prevalence
  • Tertiary Care Centers
  • beta-Lactam Resistance / drug effects
  • beta-Lactam Resistance / genetics*
  • beta-Lactamases / genetics*

Substances

  • Anti-Bacterial Agents
  • Bacterial Proteins
  • Carbapenems
  • Cephalosporins
  • Integrases
  • AmpC beta-lactamases
  • beta-Lactamases