The putative iron transport system SitABCD encoded on SPI1 is required for full virulence of Salmonella typhimurium

Mol Microbiol. 2000 Mar;35(5):1146-55. doi: 10.1046/j.1365-2958.2000.01783.x.


Salmonella typhimurium is an invasive pathogen that causes diseases ranging from mild gastroenteritis to enteric fever. During the infection process, S. typhimurium induces a number of virulence genes required to circumvent host defences and/or acquire nutrients in the host. We have used the in vivo expression technology (IVET) system to select for S. typhimurium genes that are induced after invasion of a murine cultured cell line. We have characterized a putative iron transporter in Salmonella pathogenicity island 1, termed sitABCD. The sitABCD operon is induced under iron-deficient conditions in vitro and is repressed by Fur. This locus is induced in the animal specifically after invasion of the intestinal epithelium. We show that a sit null mutant is significantly attenuated in BALB/c mice, suggesting that SitABCD plays an important role in iron acquisition in the animal.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Biological Transport
  • Carrier Proteins / genetics*
  • Genes, Bacterial*
  • Iron / metabolism*
  • Mice
  • Mice, Inbred BALB C
  • Mice, Inbred C3H
  • Mutation
  • Operon
  • Salmonella Infections / genetics
  • Salmonella Infections / metabolism*
  • Salmonella Infections / pathology
  • Salmonella typhimurium / genetics
  • Salmonella typhimurium / pathogenicity*
  • Virulence


  • Carrier Proteins
  • Iron