Antimicrobial resistance patterns and characterization of integrons in clinical isolates of Shigella from China

Can J Microbiol. 2014 Apr;60(4):237-42. doi: 10.1139/cjm-2013-0893. Epub 2014 Mar 7.

Abstract

One hundred fifty-three Shigella isolates were examined for multiple antibiotic resistance phenotypes and prevalence of class 1 and class 2 integron sequences. The gene cassettes dfrA17-aadA5, dfrA12-orfF-aadA2, and arr-3-aacA4 were found in typical class 1 integrons. The gene cassettes blaOXA-1-aadA1 and dfrA1-sat1-aadA1 were detected in atypical class 1 integrons and in class 2 integrons, respectively. This is the first report of arr-3-aacA4 cassette detected in typical class 1 integrons among Shigella isolates. Rates of antibiotic resistance were different between integron-positive and integron-negative strains (P < 0.05), and all integron-positive isolates were resistant to at least 3 different antimicrobial agents. Typical class 1 integron-positive isolates showed higher resistance rates to cefotaxime and ciprofloxacin than did integron-negative ones (P < 0.05). Typical class 1 integrons and β-lactamase genes were found in conjugative plasmids, otherwise class 2 and atypical class 1 integrons were located on chromosome. This study demonstrated the wide distribution of class 1 integrons in Shigella spp., which may lead resistance to cefotaxime and ciprofloxacin in China.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Anti-Infective Agents / pharmacology*
  • Base Sequence
  • Child
  • Child, Preschool
  • China
  • DNA, Bacterial / genetics
  • Diarrhea / microbiology
  • Drug Resistance, Multiple, Bacterial / genetics*
  • Dysentery, Bacillary / microbiology
  • Genome, Bacterial / genetics
  • Humans
  • Infant
  • Integrons / genetics*
  • Middle Aged
  • Shigella / drug effects
  • Shigella / genetics*
  • Young Adult
  • beta-Lactamases / genetics

Substances

  • Anti-Infective Agents
  • DNA, Bacterial
  • beta-Lactamases