Sydney Krystine Herzog, Lauren E. Piper


Presentation: 9:00-10:15, Kennedy Union Ballroom



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Listeria monocytogenes causes a serious infection when consumed in its typical contamination area, food. This bacteria can be extremely dangerous to sensitive populations, such as pregnant women, newborns, the geriatric population along with immunocompromised individuals. Listeria infections involve a coordinated expression of various virulence factors in response to changes in the environmental conditions. Our research team found that anaerobic propionate exposure upregulates the production of listeriolysin O (LLO) toxin at the transcriptional level. However, it is not clear whether there is a post-transcriptional regulation on LLO production. In this study, we used an IPTG-inducible LLO strain to answer the question. With 1 mM of IPTG as the transcriptional inducer, we found that anaerobic propionate significantly increased LLO production compared to no propionate control. However, with 10 mM of IPTG, the enhancement effects from propionate were absent. We then used a cell culture model of infections to test the infection outcomes of IPTG induction with or without propionate and found that propionate treatment did not result in enhanced infections. Therefore, while additional experiments are needed to confirm the effects of IPTG on transcript levels, there are likely post-transcriptional regulations to help Listeria respond to anaerobic propionate exposure.

Publication Date


Project Designation

Independent Research

Primary Advisor

Yvonne Y. Sun

Primary Advisor's Department



Stander Symposium, College of Arts and Sciences

Institutional Learning Goals

Practical Wisdom; Scholarship; Vocation

Regulation of LLO production in response to anaerobic propionate exposure