Mississippi State University
Schilling, M. Wes
Sharma, Chander Shekhar
Haque, Zahur Z.
Date of Degree
Graduate Thesis - Open Access
Food Science and Technology
Master of Science (M.S.)
College of Agriculture and Life Sciences
Department of Food Science, Nutrition and Health Promotion
The purpose of this study was to induce an oxidative-stress adaptation in Listeria monocytogenes Bug600 (serotype 1/2a) and F1057 (serotype 4b) by pre-exposing to sublethal H2O2 and alkali-stress either singly or sequentially. Our findings show that the sequential pre-exposure of cells to pH 9 for 30 min treatment followed by 50 ppm H2O2 for 30 min at 37°C yielded the highest oxidative-stress resistant phenotypes of L. monocytogenes Bug600 and F1057. The sublethal H2O2 and sublethal alkali-stress induced oxidative-stress adaptations were completely reversible within 60 min at 37°C in the absence of such sublethal stress. However, the oxidative-stress adaptation induced at 37°C was stable at 4°C over a 24 h test period in both L. monocytogenes Bug600 and F1057. Future studies will focus on the potential cross-resistance of oxidative-stress adapted L. monocytogenes serotypes 1/2a and 4b to commonly used disinfectants and GRAS antimicrobials.
De Abrew Abeysundara, Piumi, "Formation of Oxidative-Stress Resistant Phenotypes of Listeria Monocytogenes Serotypes 1/2A and 4B and their Stability at 37oC and 4oC" (2013). Theses and Dissertations. 2326.