The selC-associated SHI-2 pathogenicity island of Shigella flexneri

Mol Microbiol. 1999 Jul;33(1):74-83. doi: 10.1046/j.1365-2958.1999.01449.x.


Pathogenicity islands are chromosomal gene clusters, often located adjacent to tRNA genes, that encode virulence factors present in pathogenic organisms but absent or sporadically found in related non-pathogenic species. The selC tRNA locus is the site of integration of different pathogenicity islands in uropathogenic Escherichia coli, enterohaemorrhagic E. coli and Salmonella enterica. We show here that the selC locus of Shigella flexneri, the aetiological agent of bacterial dysentery, also contains a pathogenicity island. This pathogenicity island, designated SHI-2 (Shigella island 2), occupies 23.8 kb downstream of selC and contains genes encoding the aerobactin iron acquisition siderophore system, colicin V immunity and several novel proteins. Remnants of multiple mobile genetic elements are present in SHI-2. SHI-2-hybridizing sequences were detected in all S. flexneri strains tested and parts of the island were also found in other Shigella species. SHI-2 may allow Shigella survival in stressful environments, such as those encountered during infection.

Publication types

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

MeSH terms

  • Bacterial Proteins / genetics*
  • Chromosome Mapping
  • Chromosomes, Bacterial / genetics*
  • Cloning, Molecular
  • Colicins*
  • DNA Transposable Elements / genetics
  • DNA, Bacterial / genetics
  • Enterobacteriaceae / genetics
  • Escherichia coli / genetics
  • Genes, Bacterial*
  • Hydroxamic Acids / metabolism
  • Integrases / genetics
  • Operon
  • Sequence Alignment
  • Sequence Homology, Nucleic Acid
  • Shigella flexneri / genetics*
  • Shigella flexneri / pathogenicity
  • Species Specificity
  • Transposases / genetics
  • Virulence / genetics


  • Bacterial Proteins
  • Colicins
  • DNA Transposable Elements
  • DNA, Bacterial
  • Hydroxamic Acids
  • colicin immunity proteins
  • aerobactin
  • Integrases
  • Transposases

Associated data

  • GENBANK/AF141323