Metabolism and physiology of Listeria monocytogenes

Abstract

Compared to the rich wealth of knowledge concerning the molecular basis of Listeria monocytogenes virulence, little is known on the physiological background necessary for allowing this facultative intracellular human pathogen to survive and replicate in its natural surroundings, particularly in the host cell's cytosol. This cellular compartment appears to be the preferred site of replication, during a systemic infection caused by L. monocytogenes. Complementing earlier physiological studies, especially the more recent results obtained by comparative genomics, transcriptome, and proteome analyses, and by 13C-isotopolog perturbation studies, allow us today to draw a first (although still rather incomplete) picture of how the metabolism of these bacteria may function to facilitate efficient growth under extra- and intracellular conditions. In this chapter, we concentrate on the carbon- and nitrogen-metabolism of L. monocytogenes as deduced from these studies. Although many carbon- and nitrogen-metabolic pathways of L. monocytogenes appear to be similar to those of the extensively studied Bacillus subtilis, which like L. monocytogenes belongs to the group of low G+C gram-positive (Gp) bacteria, there seem to be some profound differences that are essential for understanding the interplay of the listerial metabolism with that of the host cells and hence may have an important impact on listerial virulence.