Improperly thermally treated compost can allow human pathogens to survive. Pathogens can regrow in finished compost due to recontamination or incomplete pathogen-kill. U.S. Environmental Protection Agency's (EPA) and U.S. Composting Council's (USCC) methodologies were compared to recover populations of inoculated non-pathogenic E. coli and pathogenic Salmonella spp. from finished compost. Two immunomagnetic separation (IMS) techniques were additionally compared for the rapid recovery of inoculated pathogenic E. coli O157:H7. Twenty-nine point-of-sale composts were obtained from 19 U.S. states. EPA methods recovered more (generic E. coli, p=0.0001) or statistically equal (Salmonella, p=0.27) amounts of inocula compared to USCC methods. Both IMS techniques identified with 3-4% false negatives among replicates. Physicochemical parameters of compost were tested as predictors of Salmonella and O157:H7 regrowth in finished compost. Salmonella and O157:H7 populations increased over three days in 48% and 52% of compost samples, respectively. No physicochemical measurements could predict the regrowth of Salmonella or O157:H7.
|Commitee:||Millner, Patricia D., Sharma, Manan, Yarwood, Stephanie|
|School:||University of Maryland, College Park|
|Department:||Environmental Science and Technology|
|School Location:||United States -- Maryland|
|Source:||MAI 52/05M(E), Masters Abstracts International|
|Subjects:||Food Science, Agriculture, Environmental science|
|Keywords:||Compost, E. coli o157:h7 salmonella, Epa method 1680 1682, Immunomagnetic separation, Pathogen regrowth, Tmecc 07.01 07.02|
Copyright in each Dissertation and Thesis is retained by the author. All Rights Reserved
The supplemental file or files you are about to download were provided to ProQuest by the author as part of a
dissertation or thesis. The supplemental files are provided "AS IS" without warranty. ProQuest is not responsible for the
content, format or impact on the supplemental file(s) on our system. in some cases, the file type may be unknown or
may be a .exe file. We recommend caution as you open such files.
Copyright of the original materials contained in the supplemental file is retained by the author and your access to the
supplemental files is subject to the ProQuest Terms and Conditions of use.
Depending on the size of the file(s) you are downloading, the system may take some time to download them. Please be