Honors Theses
Advisor
Dr. Yvonne Sun
Department
Biology
Publication Date
4-22-2026
Document Type
Honors Thesis
Abstract
Reports of Listeria monocytogenes foodborne infections continue to persist throughout the general population despite regulatory cleaning, disinfection, and recall efforts. Recently, there has been a noticeable consumer shift toward a preference for natural preservatives, disinfectants, and produce washes which utilize plant-based essential oils (EOs) as their antimicrobial agent. Clove oil and its primary component, eugenol, have been widely used in these household products and have been shown to exhibit antimicrobial activity against various pathogens, including L. monocytogenes. However, there is still much unknown about how bacterial stress responses and environmental storage conditions affect the susceptibility of Listeria monocytogenes to EOs. This study examined the role of the alternative sigma factor SigB and food-related environmental stressors in the modulation of L. monocytogenes susceptibility to clove oil and eugenol. Baseline susceptibility of wild-type and ΔsigB strains were obtained by measuring MICs and MBCs after treatment with clove oil, eugenol, or benzalkonium chloride across food-storage temperatures and with or without exposure to the common preservative, propionate. Ethidium bromide accumulation assays were performed to examine potential differences in membrane permeability. Preliminary findings show that L. monocytogenes susceptibility to clove oil and eugenol differ between strains, suggesting that the deletion of SigB alters L. monocytogenes ability to tolerate these antimicrobials. The environmental stress conditions of cold exposure and propionate treatment further influenced these patterns under eugenol treatment.
Permission Statement
This item is protected by copyright law (Title 17, U.S. Code) and may only be used for noncommercial, educational, and scholarly purposes.
Keywords
Undergraduate research
eCommons Citation
Perram, Ariana, "Influence of sigB and Environmental Food Conditions on the Susceptibility of Listeria monocytogenes to Eugenol and Clove Oil" (2026). Honors Theses. 518.
https://ecommons.udayton.edu/uhp_theses/518
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