PLASMID VIRULENCE GENE-EXPRESSION INDUCED BY SHORT-CHAIN FATTY-ACIDS IN SALMONELLA-DUBLIN - IDENTIFICATION OF RPOS-DEPENDENT AND RPOS-INDEPENDENT MECHANISMS

The Salmonella plasmid virulence spvABCD genes are growth phase regula ted and require RpoS for maximal expression in stationary phase. We id entified a growth phase-independent expression of spv which is mediate d by short-chain fatty acids. During this fatty acid-mediated expressi on of spv, RpoS is required for induction only during exponential phas e. In stationary phase, an rpoS-independent mechanism is responsible f or expression of spv.