Molecular and functional analysis indicates a mosaic structure of Salmonella pathogenicity island 2

M Hensel, T Nikolaus, C Egelseer - Molecular microbiology, 1999 - Wiley Online Library
M Hensel, T Nikolaus, C Egelseer
Molecular microbiology, 1999Wiley Online Library
Two large virulence loci encoding type III secretion systems are present on the chromosome
of Salmonella typhimurium. Salmonella pathogenicity island 2 (SPI2) is important for the
survival of S. typhimurium in host organs and forms an insertion of about 40 kb at the
tRNAVal gene. However, several indications suggested that SPI2 was not the result of a
single event of horizontal gene transfer. We characterized the portion of SPI2 towards the 30
cs boundary and performed mutational analysis to investigate the contribution of this region …
Two large virulence loci encoding type III secretion systems are present on the chromosome of Salmonella typhimurium. Salmonella pathogenicity island 2 (SPI2) is important for the survival of S. typhimurium in host organs and forms an insertion of about 40 kb at the tRNAVal gene. However, several indications suggested that SPI2 was not the result of a single event of horizontal gene transfer. We characterized the portion of SPI2 towards the 30 cs boundary and performed mutational analysis to investigate the contribution of this region to S. enterica virulence. This analysis indicates that SPI2 may be composed of at least two different genetic elements. About 15 kb of the 40 kb of SPI2 contain genes without a significant contribution to systemic infections in the model of murine salmonellosis. Our study allowed us to define genes in SPI2 important for virulence further and indicated that this locus has a complex mosaic structure.
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