• DNA microarrays and global gene expression patterns
• Genomic indexing of Salmonella and E.coli
• Salmonella virulence gene expression during infectionLag Phase
• Salmonella Infection of Chicken oviduct (SafeHouse)
• Influence of Commensal flora, immune response and behaviour on Salmonella infection (VTRI104)
• Environmental regulation of the invasion and intracellular virulence gene programmes of Salmonella: a ppGpp dependent switch

• Regulation of Salmonella SPI1 & SPI2
• Bacterial nitrate metabolism in colonisation of the mammalian gastrointestinal tract
• Analysis of factors affecting Salmonella contamination of meat during the slaughter process (Biotracer)

• "Non genetic variation" gene expression within bacterial populations (Finished)

• Nucleoid associated proteins: DNA topology and gene expression.
• Acambis project on enterotoxigenic E.coli (Finished)

The genetic and environmental regulation of Salmonella SPI1 & SPI2

Main researchers: Arthur Thompson; Sacha Lucchini

The cascade of gene expression during Salmonella infection is studied with a focus on virulence genes from the two main pathogenicity islands (SPI) of Salmonella.

SPI1 encodes a Type III secretion system, and the regulatory proteins and secreted proteins required for interaction with mammalian cells.

Less is known about SPI2, but it also encodes a Type III secretion system, regulatory proteins and "effector" proteins required for systemic mouse infection.

Regulatory studies conducted in several laboratories (including IFR) have shown that SPI1 and SPI2 genes are differentially regulated, and respond to several environmental signals. For instance, the SPI1 gene invA is induced by salt and low oxygen, and is regulated by the global gene regulator H-NS whereas other SPI1 and SPI2 genes are not.