A new chloramphenicol and florfenicol resistance gene flanked by two integron structures in Salmonella typhimurium DT104

FEMS Microbiol Lett. 1999 May 15;174(2):327-32. doi: 10.1111/j.1574-6968.1999.tb13586.x.


A new chloramphenicol resistance gene from Salmonella typhimurium DT104, designated floR, also conferring resistance to florfenicol, was characterized. Sequence analysis of the deduced FloR protein suggested that it belongs to the 12-TMS (transmembrane segments) multidrug efflux pumps family. The floR gene, and the downstream sequenced tetR and tetA tetracycline resistance genes, were surrounded by two class 1 integrons. The first one contained the resistance gene aadA2 and a deleted sulI resistance gene. The second one contained the beta-lactamase gene pse1 and a complete sulI gene. Thus, the floR gene is included in a multiresistance locus of at least 12.5 kb. Its particular organization and chromosomal location could be involved in the antibioresistance pattern stability of the DT104 Salmonella typhimurium strains.

MeSH terms

  • Anti-Bacterial Agents / pharmacology*
  • Base Sequence
  • Chloramphenicol Resistance / genetics*
  • Chromosome Mapping
  • Drug Resistance, Microbial / genetics
  • Drug Resistance, Multiple / genetics
  • Genes, Bacterial
  • Integrases / genetics
  • Molecular Sequence Data
  • Plasmids / genetics
  • Salmonella typhimurium / drug effects*
  • Salmonella typhimurium / genetics*
  • Sequence Analysis, DNA
  • Thiamphenicol / analogs & derivatives*
  • Thiamphenicol / pharmacology


  • Anti-Bacterial Agents
  • florfenicol
  • Integrases
  • Thiamphenicol

Associated data

  • GENBANK/AF118107
  • GENBANK/D37826
  • GENBANK/S52438