The Relationship Between Iron Metabolism and the Growth, Survival and Pathogenicity of Salmonella

The Salmonella are of major importance as food-borne pathogens. Iron acquisition is a vital aspect of the physiology and pathogenicity of these bacteria. Research shows that growth of the closely-related E. coli is strictly dependent on iron supply. In the absence of external iron, E. coli utilises intracellular iron stores. Preliminary studies with Salmonella typhimurium and S. gallinarum show that mutants lacking the iron-storage machinery exhibit reduced gut colonisation capacity and weakened virulence. <P>
It is proposed to confirm and extend this research by thoroughly assessing the importance of bacterial iron stores in virulence, gut colonisation and in growth under iron restriction. We will also attempt to identify the transporters used by Salmonella to take up iron during intracellular colonisation. These studies will thus address important, yet unanswered, questions in the use of iron by pathogens in various host niches. We will also assess the sustainability of the ftnA mutant as a vaccine strain.