Phenotypic and molecular characterization of CTX-M extended-spectrum beta-lactamase-producing Escherichia coli isolates in Shiraz, Iran

Rev Soc Bras Med Trop. 2015 Jul-Aug;48(4):479-82. doi: 10.1590/0037-8682-0315-2014.

Abstract

Introduction: The aim of this study was to detect the prevalence of the extended-spectrum beta-lactamase (ESBL)-encoding CTX-M gene in Escherichia coliisolates.

Methods: Phenotypic screening of 376 E. coli isolates for ESBL was conducted using disk diffusion. ESBL-producing isolates were tested using PCR and specific primers. The bla(CTX-M) cluster was identified using the RFLP method, and its genotype was sequenced.

Results: From 202 ESBL-producing E. coli , 185 (91.5%) possessed CTX-M genes. CTX-M-1 subtypes were found in 98% of the isolates. The bla(CTX-M) gene was identical to CTX-M-15.

Conclusions: A high prevalence of CTX-M-1-producing E. coli apparently exists in Shiraz, Iran.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anti-Bacterial Agents / pharmacology
  • Bacterial Proteins / genetics
  • DNA, Bacterial / analysis
  • Disk Diffusion Antimicrobial Tests
  • Electrophoresis, Gel, Pulsed-Field
  • Escherichia coli / drug effects
  • Escherichia coli / enzymology*
  • Escherichia coli / genetics*
  • Genotype
  • Humans
  • Iran
  • Phenotype
  • Polymorphism, Restriction Fragment Length
  • Sequence Analysis, DNA
  • beta-Lactamases / biosynthesis
  • beta-Lactamases / genetics*

Substances

  • Anti-Bacterial Agents
  • Bacterial Proteins
  • DNA, Bacterial
  • beta-lactamase TEM-3
  • beta-Lactamases