Soil amended with manure has been implicated as a source of produce contamination leading to foodborne gastrointestinal-disease outbreaks. While current composting guidelines require temperatures ≥ 55°C for 3 days to destroy bacterial pathogens, these requirements have not been evaluated for all pathogens. Investigation of parasite survival in manure required development of a flow cytometry method integrating the cell-impermeant viability dye SytoX for simultaneous quantification and viability assessment of Cryptosporidium and Giardia oocysts/cysts. Further studies will be required to apply this method to investigate thermal reduction in parasites. Studies conducted with bacterial pathogens indicated that E. coli O157:H7 survived longer than other pathogens at 50°C to 55°C. Listeria monocytogenes survived significantly better in chicken manure compared to cow manure at 50°C to 55°C. Results suggest composting guidelines are adequate for bacterial pathogen reduction; however, testing for E. coli O157 along with Salmonella may increase confidence in compost safety.
Identifer | oai:union.ndltd.org:uottawa.ca/oai:ruor.uottawa.ca:10393/32093 |
Date | January 2015 |
Creators | Cooper, Ashley |
Contributors | Mattison, Kirsten |
Publisher | Université d'Ottawa / University of Ottawa |
Source Sets | Université d’Ottawa |
Language | English |
Detected Language | English |
Type | Thesis |
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