Integron-associated antibiotic resistance in enteroaggregative and enteroinvasive Escherichia coli

Microb Drug Resist. 2004 Spring;10(1):27-30. doi: 10.1089/107662904323047763.

Abstract

Ten enteroinvasive (EIEC) and 25 enteroaggregative (EaggEC) E. coli strains isolated from Senegalese patients were analyzed for their integron content. All strains were resistant to at least two antibiotics. Four EIEC and 15 EaggEC were found to carry a class 1 integron. An identical integron carrying a single dfrA5 cassette, conferring resistance to trimethoprim, was identified in all four EIEC strains. Five EaggEC strains harbored an integron with a single cassette, dfrA7, while the remaining 10 strains carried two integrons, one with a single cassette, aadA1a conferring resistance to streptomycin and spectinomycin, and the second one bearing two cassettes, dfrA13 and oxa5, the later being a beta-lactam resistance cassette. The presence of these integrons is worrying, because trimethoprim is largely used for diarrheal disease therapy in Africa. Thus, the presence of integrons in diarrheagenic strains is of public health importance because a limited number of antibiotics are available in developing countries.

MeSH terms

  • Chromosome Mapping
  • Conjugation, Genetic
  • Drug Resistance, Bacterial / genetics*
  • Escherichia coli / genetics*
  • Escherichia coli / pathogenicity
  • Escherichia coli Infections / genetics*
  • Escherichia coli Infections / microbiology
  • Gene Transfer, Horizontal
  • Genes, Bacterial / genetics
  • Humans
  • Integrons / genetics*
  • Microbial Sensitivity Tests
  • Polymorphism, Genetic
  • Reverse Transcriptase Polymerase Chain Reaction