Identification of host-specific colonization factors of Salmonella enterica serovar Typhimurium
Article first published online: 22 SEP 2004
Volume 54, Issue 4, pages 994–1010, November 2004
How to Cite
Morgan, E., Campbell, J. D., Rowe, S. C., Bispham, J., Stevens, M. P., Bowen, A. J., Barrow, P. A., Maskell, D. J. and Wallis, T. S. (2004), Identification of host-specific colonization factors of Salmonella enterica serovar Typhimurium. Molecular Microbiology, 54: 994–1010. doi: 10.1111/j.1365-2958.2004.04323.x
- Issue published online: 8 OCT 2004
- Article first published online: 22 SEP 2004
- Accepted 26 July, 2004.
The severity of infections caused by Salmonella enterica serovar Typhimurium varies depending on the host species. Numerous virulence genes have been identified in S. Typhimurium, largely from studies in mice, but their roles in infections of other species remain unclear. In the most comprehensive survey of its kind, through the use of signature-tagged mutagenesis of S. Typhimurium we have identified mutants that were unable to colonize calf intestines, mutants unable to colonize chick intestines and mutants unable to colonize both species. The type three secretion systems encoded on Salmonella pathogenicity islands (SPIs) 1 and 2 were required for efficient colonization of cattle. However, disruption of these secretion systems only caused a minor defect in S. Typhimurium colonization of chicks. Transposon insertions in SPI-4 compromised S. Typhimurium colonization of cattle, but not chicks. This is the first data confirming a role for SPI-4 in pathogenesis. We have also been able to ascribe a role in colonization for cell surface polysaccharides, cell envelope proteins, and many ‘housekeeping’ genes and genes of unknown function. We conclude that S. Typhimurium uses different strategies to colonize calves and chicks. This has major implications for vaccine design.