Listeria monocytogenes, Salmonella and Campylobacter combined are responsible for the majority of foodborne disease hospitalizations and over 1200 deaths annually in the U.S. alone. Although raw poultry has been identified as a source of these pathogens, most microbiological studies have focused on broilers with little attention given to turkey processing. The purpose of this research was to investigate the prevalence of select pathogens (L. monocytogenes, Salmonella spp., and Campylobacter spp.) and microbiological indicators (Enterococcus spp.) in the turkey processing environment. Environmental samples were collected in one Southeastern processing facility using swab methods at two month intervals over a period of 14 months. Samples were taken from conveyors, drains, walls and various food contact surfaces. Isolation and identification of bacteria was done using the USDA-FSIS Microbiology Laboratory Guidebook protocols. The prevalence of contamination was 11.5%, 7.4%, and 0.4% for L. monocytogenes, Salmonella, and Campylobacter, respectively. Enterococcus spp., an environmental indicator of fecal contamination, were isolated from over >75% of the samples screened. Salmonella isolates were typed using pulsed-field gel electrophoresis (PFGE) and Enterococcus isolates were speciated by PCR with antibiotic resistance profiles characterized using the SensiTitre system. A diverse set of relatively non-persistent Salmonella strains were obtained from the processing environment, as evaluated by PFGE. Thirty-nine percent of the Enterococcus isolates were speciated as E. faecium and 55% were E. faecalis. Both E. faecalis as E. faecium strains were susceptible to most antibiotics of human clinical relevance. Thirty-three L. monocytogenes strains were screened for their biofilm formation capabilities using a microtiter well assay. None of the strains formed a biofilm in monoculture; however, sixteen of the strains were able to form a biofilm in the presence of another organism. Data collected in prevalence studies such as this one can help processors identify contamination frequency and sites in an effort to control resident pathogenic bacteria in the processing environment.
| Identifer | oai:union.ndltd.org:NCSU/oai:NCSU:etd-05182005-155133 |
| Date | 31 May 2005 |
| Creators | Stam, Christina Nicole |
| Contributors | Sophia Kathariou, Brian Sheldon, Lee-Ann Jaykus |
| Publisher | NCSU |
| Source Sets | North Carolina State University |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://www.lib.ncsu.edu/theses/available/etd-05182005-155133/ |
| Rights | unrestricted, I hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to NC State University or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. |
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