Fate of Escherichia coli O157:H7 and Salmonella from contaminated manure slurry applied to soil surrounding tall fescue

摘要

AIM: To investigate the potential transfer of Escherichia coli O157:H7 and Salmonella from contaminated manure slurry into the tissue of tall fescue plants. METHODS AND RESULTS: Tall fescue plants (n = 50) were fertilized with a manure slurry inoculated with E. coli O157:H7 and Salmonella. Soil was collected and tall fescue plants (n = 10 per day) harvested on day 1, 2, 4, 8, and 14 after manure slurry fertilization. Soil samples were positive for E. coli O157:H7 on all days and on day 1, 2, 8, and 14 for Salmonella. None of the plant tissue samples were positive for E. coli O157:H7 on day 1 or 2; however, 20%, 30% and 40% of plant tissue samples were positive for E. coli O157:H7 on day 4, 8, and 14, respectively. CONCLUSIONS: It may be possible that E. coli O157:H7 can become transmitted and internalized into tall fescue plant tissue within 4 days after exposure to an E. coli O157:H7-contaminated manure slurry. Salmonella did not appear to be transferred to tall fescue plant tissue. SIGNIFICANCE AND IMPACT OF THE STUDY: Faeces contaminated with E. coli O157:11H7 may be one means by which grazing ruminants spread bacterial pathogens to additional animals.