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.
| Identifer | oai:union.ndltd.org:ndsu.edu/oai:library.ndsu.edu:10365/28387 |
| Date | January 2017 |
| Creators | Smith, Sara Jean |
| Publisher | North Dakota State University |
| Source Sets | North Dakota State University |
| Detected Language | English |
| Type | text/thesis |
| Format | application/pdf |
| Rights | NDSU policy 190.6.2, https://www.ndsu.edu/fileadmin/policy/190.pdf |
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