Survival of Escherichia coli and Salmonella Typhimurium in slurry applied to clay soil on a Danish swine farm

• Published in: Preventive veterinary medicine 2005-07, Vol.69 (3), p.213-228
• Main Authors: Boes, J., Alban, L., Bagger, J., Møgelmose, V., Baggesen, D.L., Olsen, J.E.
• Format: Article
• Language: English
• Subjects: agricultural land; Aluminum Silicates; Animals; application methods; Bacterial decline; clay soils; Computer Simulation; Denmark; duration; Escherichia coli; Escherichia coli - growth & development; Escherichia coli Infections - microbiology; Escherichia coli Infections - veterinary; food animals; grain crops; harrowing; liquid manure; Manure - microbiology; manure handling; microbial detection; Models, Biological; Multi-resistant DT104; pathogen survival; pig manure; Pilot Projects; plowing; Salmonella Infections, Animal - microbiology; Salmonella Typhimurium; Salmonella typhimurium - growth & development; seedlings; Simulation; slurries; Slurry; soil injection; Soil Microbiology; swine; Swine - microbiology; Triticum aestivum; winter wheat
• ISSN: 0167-5877; 1873-1716
• DOI: 10.1016/j.prevetmed.2005.02.007

A pilot study was carried out on a Danish swine farm infected with multi-resistant Salmonella Typhimurium DT104 (MRDT104). We aimed to (1) investigate to which degree the decline of Escherichia coli and Salmonella in swine slurry applied to farmland depended on the application method; (2) estimate the survival times of E. coli and Salmonella in the soil surface following deposition of naturally contaminated pig slurry; and (3) simulate survival of Salmonella in different infection levels using E. coli data as input estimates. Slurry was deposited by four different methods: (1) hose applicator on black soil followed by ploughing and harrowing; (2) hose applicator on black soil followed only by harrowing; (3) hose applicator on a field with winter-wheat seedlings without further soil treatment; (4) slurry injector on a field with winter-wheat seedlings without further soil treatment. E. coli and Salmonella could not be detected at all in soil following treatment 1. Following the other treatments, E. coli was not detected in soil samples after day 21 and Salmonella was no longer detected after day 7. Simulation results showed that clinical (4 log CFU g −1) and sub-clinical Salmonella levels (2500 CFU g −1) would fall below the detection limit within 10 or 5 days, respectively. Analysis of samples from 62 Danish MRDT104-infected swineherds showed that nearly 75% of these herds had low levels of MRDT104 (