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ARS Home » Northeast Area » Beltsville, Maryland (BARC) » Beltsville Agricultural Research Center » Environmental Microbial & Food Safety Laboratory » Research » Research Project #431870

Research Project: Characterization and Mitigation of Bacterial Pathogens in the Fresh Produce Production and Processing Continuum

Location: Environmental Microbial & Food Safety Laboratory

Project Number: 8042-32420-009-019-S
Project Type: Non-Assistance Cooperative Agreement

Start Date: May 1, 2017
End Date: Mar 30, 2022

1) Investigate the population dynamics of non-pathogenic Escherichia coli (E. coli) and Non-O157 Shiga Toxigenic E. coli in soils amended with Biological Soil Amendments of Animal Origin (BSAAO) and their potential for transfer to produce surfaces. 2) Identify specific factors which may impact the survival of Salmonella spp. and STEC O157 in soils which may also correlate to higher transfer coefficients onto commodities grown in soils amended with untreated BSAAO.

Plots or pots in either fields, high tunnels, or growth chambers containing soil amended with various animal manure with be inoculated with non-pathogenic E. coli, shiga-toxigenic E. coli, or Salmonella spp. in two consecutive growing seasons. Populations of enteric pathogens will be monitored, especially after irrigation or rainfall events, to determine of increases in moisture will results in increases in target pathogen populations. Both covered (plastic-mulched) and uncovered plots / pots will be monitored. Crops (radishes, cucumbers) planted in these soils will also be analyzed for the presence of pathogens as well. Physicochemcial analysis of soil and manure-amended soils will also be executed. Investigations into specific BSAAO from poultry feces (poultry litter or heat-treated poultry litter pellets) will also be conducted to determine of these BSAOO’s can transfer a high population to growing crops then others. Similarly, differences in pathogen population in response to irrigation or moisture events will also be evaluated. Bacterial isolates lacking specific stress response genes will be used to determine specific interactions between BSAAO type and genotypic properties of pathogens in persistence in amended soils. NEA Statistics group will consulted to provide statistical analysis. This approach will provide a determination of what specific interactions influence bacterial population fluctuations in BSAAO-amended soils and whether or not these fluctuations affect the amount of bacteria transferred manure-amended soils to growing fruit and vegetable crops.