Grischa Chen

Position title: 2014-2015, 2015-2016

Research Focus: Listeria monocytogenes is a deadly food-borne pathogen. The ability of L. monocytogenes to cause disease depends on it’s ability to replicate and survive in the cytosol of host cells such as macrophages, hepatocytes, and epithelial cells. Unfortunately, not much is known about the strategies L. monocytogenes uses to survive in the host cytosol. Grischa’s project has focused on understanding the genetic factors that allow L. monocytogenes to colonize this host environment and the host defenses that may restrict cytosolic invasion by bacteria. Prior to receiving the Microbes in Health and Disease Training Grant he had identified several mutants which had significant survival defects during intracellular replication in macrophages but had not yet characterized these mutants in detail yet. He has focused his research on studying a subset of the bacteriolysis mutants which are auxotrophic for menaquinone, an essential component of the electron transport chain in bacteria. In investigating the role of menaquinone in cytosolic survival of L. monocytogenes we now have a better understanding of why these mutants cannot survive in macrophages.