The Prevalence of Escherichia. coli O157:H7 in small scale cow-calf operations in Louisiana.

摘要

Between June and September, 2011, fecal, water and sediment samples and water equipment swabs were collected from small beef cattle farms throughout the state of Louisiana and examined for the presence of Escherichia coli O157:H7. The presence of E. coli O157:H7 was determined by sample enrichment and immunomagnetic separation (IMS) followed by testing with latex agglutination. Percent recovery of the pathogen was for five locations, Slaughter, Zachary, Bastrop, Thibodaux and Opelousas, were compared to the percent recovery found in Baton Rouge, LA. During the first sample collection, E. coli O157:H7 was recovered from 11--36.6% of fecal samples from all locations, up to 60% of water samples from all locations, up to 50% of sediment samples from all locations and up to 25% of water equipment swabs from all locations. During the second sample collection, E. coli O157:H7 was recovered from 6.7--36.7% of fecal samples from all locations, up to 50% of water samples from all locations, up to 75% of sediment samples from all locations and up to 25% of water equipment swabs from all locations. We found that pastures sampled in Thibodaux, LA consistently had lower pathogen recovery rates as compared to Baton Rouge, which suggests that regional location and farming practices may be resulting in decreased prevalence of the pathogen. Such results indicate that small-scale beef cattle operations in Louisiana have the potential to become a source of future outbreaks of E. coli O157:H7 infection and can be used to recommend farming practices that limit carriage of E. coli O157:H7 in beef cattle, thus reducing consumer risk for infection.