Atypical class 1 integron coexists with class 1 and class 2 integrons in multi-drug resistant Shigella flexneri isolates from China

Curr Microbiol. 2011 Mar;62(3):802-6. doi: 10.1007/s00284-010-9790-3. Epub 2010 Oct 26.

Abstract

The antimicrobial resistance and the character of integrons were determined in 58 Shigella flexneri strains isolated from China. All isolates were multi-drug resistant and found to carry integrons of class 1 (94.8%), class 2 (100%), or both (94.8%). No intI3 was detected. The typical class 1 integrons were found in conjugative plasmids and could be transferred to the recipient E. coli DH5α. The gene cassettes of typical class 1 integrons dfrA17-aadA5 and dfrA12-orfF-aadA2 were detected in 54 strains (93.1%) and 1 strain, respectively. Atypical class 1 integrons located on the chromosome with gene cassettes bla (oxa-30)-aadA1 were detected in 55 isolates (94.8%). All the intI2 positive isolates carried gene cassettes dfrA1-sat1-aadA1. To our knowledge, this is the first report that atypical and typical class 1 integrons coexisted with class 2 integron in multi-drug resistant S. flexneri strains.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • China
  • Chromosomes, Bacterial
  • DNA, Bacterial / chemistry
  • DNA, Bacterial / genetics*
  • Drug Resistance, Multiple, Bacterial*
  • Dysentery, Bacillary / microbiology*
  • Genes, Bacterial
  • Humans
  • Integrons*
  • Molecular Sequence Data
  • Sequence Analysis, DNA
  • Shigella flexneri / drug effects*
  • Shigella flexneri / genetics*
  • Shigella flexneri / isolation & purification

Substances

  • DNA, Bacterial

Associated data

  • GENBANK/EF634237
  • GENBANK/FJ895301
  • GENBANK/FJ895302
  • GENBANK/GQ214137