Rapid, Transient, and Proportional Activation of σB in Response to Osmotic Stress in Listeria monocytogenes

The osmotic activation of sigma B (sigma(B)) in Listeria monocytogenes was studied by monitoring expression of four known sigma(B)-dependent genes, opuCA, lmo2230, lmo2085, and sigB. Activation was found to be rapid, transient, and proportional to the magnitude of the osmotic stress applied, features that underpin the adaptability of this pathogen.