|ROBERTS, B - Mississippi State University|
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 7/30/2011
Publication Date: 7/30/2011
Citation: Roberts, B.N., McLaughlin, M.R., Brooks, J.P. 2011. Survival of bacterial and viral pathogens in swine effluent, cattle manure, and biosolids when applied to Southeastern U.S. soils [abstract]. AFRI Project Directors Meeting, Milwaukee, WI, July 30, 2011. Presentation Only.
Technical Abstract: In the United States, greater than 100 million dry tons of manure and 7 million dry tons biosolids are produced on a yearly basis. This scale of residual waste production requires large swaths of land for disposal and often times have come under scrutiny as a result of this demand. Environmental and public-health concerns associated with waste management involve pathogen survival and potential transport following land application. Pathogen survival traits are not universal amongst strains within a species and are highly influenced by soil type, climate, and waste residual. Methods: The focus of this study was to determine the inactivation rates of common food-borne pathogens and coliphage. Salmonella, Campylobacter, Listeria, Escherichia coli O157:H7, Clostridium perfringens, MS2, and ØX174, were seeded in four waste matrices and applied to two soil types (sandy loam, clay loam) having two incorporation plans (incorporated, non-incorporated). Waste matrices comprised Class B biosolids, swine effluent, cattle manure, and phosphate buffered saline (PBS) as a control. Microcosms were incubated for 210 days with cultivable bacteria measured at each point. Results: Salmonella and C. perfringens persisted for longer periods of time when compared to all other bacteria; the presence of cattle manure enhanced survival of Salmonella and was generally present through day 30 for all wastes while day 60 for cattle manure. Campylobacter and Listeria were below detection limits (~200 cfu g-1) by day 21. Clostridium perfringens was more able to survive in biosolids and swine effluent, and persisted regardless of waste, soil, or management. The presence of biosolids allowed MS2 to persist for a longer period of time, while ØX174 survival was not affected by residual matrix. Both phage were below detection limits in all wastes by day 90. Significance: Class B biosolids and cattle manure appeared to sustain the inoculated bacteria and phage and the calculation of inactivation rates for each treatment/pathogen combination may yield variable rates which can be used in future quantitative microbial risk analyses.