Date of Award

2017

Publisher

North Dakota State University

Document Type

Thesis

Degree Awarded

Master of Science (MS)

Program

Microbiology

Department

Microbiological Sciences

College

Agriculture, Food Systems and Natural Resources

Faculty Advisor

Bergholz, Teresa M.

Description

Outbreaks of Listeria monocytogenes, Salmonella, and Escherichia coli are increasingly attributed to fresh produce. Current control measures have been assessed for decades, with no alternatives adopted. Sources were identified, reducing flhD transcription and biofilm amounts nearly 2-fold. β-phenylethylamine (PEA), reduced growth and biofilm 96% and 70%, respectively. Curli production was assessed and found to be microorganism-, strain-, and/or serotype-dependent. Reporter fusions were constructed, evaluating expression of Listeria cellulose protein (Lcp). Plcp was not impacted by conditions used. Conditions were then used in attachment of L. monocytogenes to stainless steel. Attachment was significantly reduced by 5 ppm chlorine and 2% lysate. Small molecules could be alternatives to current control measures. More research is needed on what induces curli production. Controls confirm that reporter fusions are an effective way to discover signals impacting gene expression. Attachment/expression assays, indicate that something other than Lcp are responsible for changes in attachment to stainless steel.

Rights

NDSU policy 190.6.2

Rights Link

https://www.ndsu.edu/fileadmin/policy/190.pdf

Author ORCID Identifier

0000-0003-1630-8942

Handle Identifier

https://hdl.handle.net/10365/28387

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