|Wells, James - Jim|
|Bono, James - Jim|
|Kalchayanand, Norasak - Nor|
|SUSLOW, TREVOR - University Of California|
|LOPEZ-VELASCO, GABRIELA - University Of California|
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 4/15/2014
Publication Date: 5/8/2014
Citation: Berry, E.D., Wells, J., Durso, L.M., Bono, J.L., Friesen, K.M., Woodbury, B.L., Kalchayanand, N., Norman, K.N., Suslow, T.V., Lopez-Velasco, G., Millner, P.D. 2014. Effect of proximity to a cattle feedlot on Escherichia coli O157:H7 contamination of leafy greens and evaluation of the potential for bioaerosol and pest fly transmission. [Abstract]. Western Food Safety Summit, May 8-9, 2014, Salinas, CA. poster session.
Technical Abstract: Recent foodborne outbreaks linked to spinach and lettuce emphasize the need for information regarding E. coli O157:H7 dissemination from cattle production. Project objectives were to evaluate the impact of proximity to a cattle feedlot on E. coli O157:H7 contamination of leafy greens and to examine the potential for dissemination by bioaerosols and pest flies. In each of two years, leafy greens were planted to nine plots located 200, 400, and 600 feet from a cattle feedlot (3 plots each distance). Feedlot surface manure (FSM), leafy greens, air samples, and pest flies were collected and analyzed throughout June to September each year. The average prevalence of E. coli O157:H7 in FSM was 72%. Overall, E. coli O157:H7 was recovered from 3.2, 2.2, and 1.8% of leafy green samples at 200, 400, and 600 feet, respectively. Although E. coli O157:H7 was not recovered from 1000-liter air samples at any location, total E. coli were recovered from air samples at the feedlot edge and all three plot distances, indicating that airborne transport of the pathogen can also occur. On some days, there were decreases in total E. coli concentrations in air samples as distance from the feedlot increased (P < 0.05). Over both years, the percentage of E. coli O157:H7-positive fly pools was higher (P < 0.05) at the feedlot edge compared to 200, 400, and 600 feet. This information is critical for understanding the risks associated with growing leafy greens in close proximity to cattle production.