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ARS Home » Northeast Area » Beltsville, Maryland (BARC) » Beltsville Agricultural Research Center » Environmental Microbial & Food Safety Laboratory » Research » Publications at this Location » Publication #337560

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

Location: Environmental Microbial & Food Safety Laboratory

Title: Survival of generic E. coli and Listeria spp. populations in dairy compost- and poultry litter compost-amended soils in the Northeastern United States

Author
item LIMOGES, MARIE - UNIVERSITY OF VERMONT
item NEHER, DEBORAH - UNIVERSITY OF VERMONT
item WEICHT, THOMAS - UNIVERSITY OF VERMONT
item Millner, Patricia
item Sharma, Manan
item DONNELLY, CATHERINE - UNIVERSITY OF VERMONT

Submitted to: International Association for Food Protection
Publication Type: Abstract Only
Publication Acceptance Date: 3/17/2017
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Introduction:The FDA FSMA standards stipulate composting conditions that meet acceptable treatments for use of manure/poultry litter-based biological soil amendments of animal origin (BSAAO). Application of FSMA-compliant BSAAO to soils for production of fresh produce is expected to result in reduced risk of pathogen contamination on the harvested produce when other stipulations in the Produce Safety rule are also implemented. However, meteorological conditions, geographic location, application methods, soil type, and bacterial populations can influence the presence of pathogenic bacteria, or their indicators (e.g., generic E. coli) and potential produce contamination. Purpose:Evaluate survival of non-pathogenicE. coli (gEc) andListeria spp.in tilled plots with bothdairy and poultry litter composts in the Northeastern U.S. Methods:Replicated field plots (2m2, n=24) of Loamy (L) or Sandy (S) soils were tilled and amended with dairy compost (DC), poultry litter compost (PLC), or no compost (NC). These plots were inoculated with a three-strain cocktail of rifampicin-resistant gEcat a rate of 8.7 log CFU/m2. Colony count and most probable number (MPN)methods were used to determine persistence of gEc in these plots over 104 days post-inoculation (dpi). Detection of indigenous Listeria spp. werealso examined in all plots. Results:At 104 dpi, inoculated gEc survived at higher populations in PLC plots (3.5-3.80 log MPN/gdw) in comparison to DC plots (0.06-3.8 log MPN/gdw) and NC plots (0.6-1.3 log MPN/gdw). Populations of gEc and native E. coli after rainfall were independent of soil type. Listeria spp. were found in PLC and DC, but not in NC plots. Significance:Results are consistent with those from studies conducted in other regions of the US that show that poultry litter-based BSAAO support greater numbers and longer periods of persistence in field soils of gEc than dairy-based BSAAO.