• 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)

Lag Phase

Main Researcher: Chris Rice

Little is known about the earliest stages of growth in Salmonella and how this important pathogen adapts itself to new conditions. By using genomics and transcriptomics as principle methods, this project aims to discover how Salmonella responds to nutrient upshift and change in temperature allowing it to grow rapidly when presented with more favourable conditions.

We have recently made an exciting breakthrough in understanding how Salmonella begins growth. In a previous CASE studentship between IFR and CCFRA, to be completed in September 2006, we discovered that extensive transcription occurs during the “silent” lag phase of growth at 25OC. Our transcriptomic approach has suggested certain cellular functions to be required for growth initiation, including metal transport and the repair of protein damage. This new CASE studentship project will test several hypotheses concerning the mechanism that underpins the physiological processes needed for initiation of bacterial growth. The successful applicant will benefit from our comprehensive set of gene expression data, and will ask two questions:

First, the effect of temperature shift upon the process of growth initiation will be determined. Changes in temperature are often associated with outbreaks of food poisoning; for example, pathogenic bacteria are able to commence growth when moved to a favourable situation, such as being switched from 4 C to room temperature, and go on to cause disease when food is ingested by humans. The basis of growth initiation following temperature shift will be determined by a functional genomic approach. We will compare the findings with our 25 C data, to learn whether or not bacteria use a single unified strategy to begin growth, or whether this is temperature-dependent.

Second, the resulting hypotheses concerning the mechanisms required for bacterial growth initiation will be tested. This part of the project should provide experimental evidence for the key processes that must occur before bacteria can begin replication