A study was performed to assess the validity of the BAX automated polymerase chain reaction system (DuPont Nutrition & Health, Wilmington, Delaware) to detect the shedding of Salmonella species in bovine fecal samples. A total of 133 bovine fecal samples that were submitted to the Cornell University Animal Health Diagnostic Laboratory for Salmonella culture were also tested in the BAX system with a modified version of the manufacturer's enrichment protocol. Using culture as the gold standard test, the BAX system was found to have a sensitivity of 85.7% and a specificity of 90.5%. There was excellent agreement (κ = 0.71, standard error = 0.072) and no significant differences between the 2 methods (McNemar χ(2) = 0.180).
Keywords: Cattle; Salmonella; feces; polymerase chain reaction; validation.