Recovery of antimicrobial-resistant Escherichia coli after storage of bovine feces in Cary-Blair medium.

The effect of storing bovine feces in Cary-Blair medium on the recovery of antimicrobial-resistant Escherichia coli was investigated. Feces from cattle at a research feedlot (n = 50) and at a commercial feedlot (n = 46) were processed immediately or after storage in Cary-Blair medium for 8 days at 5 degrees C. Total, ampicillin-resistant, and tetracycline-resistant E. coli were isolated. The number of total E. coli decreased slightly after storage (0.19 log units; p < 0.001), but storage of feces in Cary-Blair medium did not affect recovery of ampicillin- or tetracycline-resistant E. coli.