PCR-ELISA detection of Escherichia coli in milk.

AIMS The purpose of this study was to develop a reliable molecular procedure for the detection of Escherichia coli in milk. METHODS AND RESULTS Robust and expeditious DNA extraction and PCR techniques were evaluated using Enzyme-Linked Immunosorbent Assay (ELISA) detection of biotin-labelled amplicons to facilitate optimal detection of E. coli DNA. CONCLUSIONS It was found that 5 E. coli colony-forming units (cfu) could be detected per PCR reaction using the PCR-ELISA system, equating to a sensitivity of detection of 100 E. coli cfu ml(-1) pasteurized milk. SIGNIFICANCE AND IMPACT OF THE STUDY This approach should facilitate evaluation of milk contamination and enable rapid detection of E. coli mastitis, leading to correct deployment of relevant antibiotic therapy and improved animal welfare.