Theses and Dissertations

Issuing Body

Mississippi State University

Advisor

Kiess, Aaron S.

Committee Member

Sharma, Chander Shekhar

Committee Member

Nannapaneni, Ramakrishna

Date of Degree

1-1-2017

Document Type

Graduate Thesis - Open Access

Abstract

The effect of exposure to sub-lethal chlorine stress on Salmonella enterica serotypes Typhimurium and Heidelberg was examined in this study. Both serotypes demonstrated an acquired tolerance to chlorine with the adapted cells growing in concentrations above the MIC. Chlorine induced a morphological change to the rugose variant in Salmonella. The biofilm formation of the adapted and control cells was tested on food-contact surfaces at room temperature and 37°C. The chlorineapted rugose formed stronger biofilms (P < 0.05) when compared to smooth (adapted and control) on both surfaces tested and at both temperatures. The possibility of crossaptation to antibiotics and low pH was evaluated. Adapted rugose showed reduced susceptibility against some of the antibiotics tested. Chlorine does not aid in the survival of Salmonella enterica at low pH. Chlorine stress can select for tolerant Salmonella cells that attach strongly to food-contact surfaces and after some time may become less susceptible to antimicrobials.

URI

https://hdl.handle.net/11668/17589

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