Persistence of Human Pathogens in Manure-Amended Australian Soils Used for Production of Leafy Vegetables

摘要: Incorporation of manures into soil can add nutrients, improve structure and enhance biodiversity, thereby improving the sustainability vegetable production systems. Unfortunately, also potentially contain human enteric pathogens. To reduce risk contamination, Australian guidelines recommend a withholding period 90 days between manure application harvest for high-risk products such as leafy salad greens. Our study examined appropriateness these under conditions replicating those on commercial farm. Cow poultry litter with/without addition non-pathogenic strains Escherichia coli (E. coli), Listeriainnocua Salmonella sv. sofia were added to sandy clay loam soils typical used grow vegetables. Bacterial populations monitored in crops cos lettuce during spring (A), summer (B) autumn (C) trials, with testing conducted by laboratory. Significant declines E. occurred within 6 16 all trials. Modelling indicated that would be at or close limit detection 50 combinations tested. A 2–3 log die-off spp. three weeks. However, occasional detections continued throughout trial A. As result, probability after fell from 1.0 0.1 0.02 trials B C, respectively, but remained 0.44 Listeria was most persistent not detected maturity. While this limited scope, results suggest day significantly reduces pathogens field conditions.