Listeriolysin O production is regulated by SCFAs and oxygen in Listeria monocytogenes
Listeria monocytogenes (LM) is foodborne pathogen that secretes listeriolysin O (LLO), a pore-forming toxin to establish its intracellular life cycle inside host cells. However, how the environment in the intestine that has both an oxygen gradient (low oxygen to no oxygen) and is enriched in short chain fatty acids (SCFAs) effects LM virulence regulation and pathogenesis has not been determined. To better understand LLO production in response to relevant environmental conditions found during LM transit through the intestinal lumen, a reporter strain and hemolytic assays were used to examine the effect of SCFAs on the transcription and the activity of LLO, respectively. We characterized the LM membrane fatty acid composition in response to SCFAs using FAME analysis. This allowed us to examine the role of membranes as an intermediate signal in LM response to SCFAs. In total, we found that that transcription and LLO production was significantly affected by SCFAs and that LM response to SCFAs was influenced by oxygen. Significant alterations in membrane fatty acids were also seen in SCFA-treated LM. Therefore, LM has the capability of responding to the SCFA-rich environment, in both virulence gene regulation and fatty acid metabolism, during intestinal transit and that individual variations in SCFA abundance may contribute to susceptibility to LM infections.
Yvonne Y Sun
Primary Advisor's Department
Stander Symposium poster
"Listeriolysin O production is regulated by SCFAs and oxygen in Listeria monocytogenes" (2018). Stander Symposium Posters. 1294.