Detection of Verotoxin Genes VT 1 and VT 2 in Escherichia coli O157:H7 in Minced Beef Using Immunocapture and Real-Time PCR

Escherichia coli O157:H7 is a highly virulent pathogen that causes severe food poisoning in humans. Many outbreaks involving this pathogen have been linked to minced beef. A protocol is presented here to detect E. coli O157:H7 in minced beef. The method consists of an enrichment step in modified tryptone soya broth, followed by immunomagnetic separation and extraction of deoxyribonucleic acid. Real-time polymearse chain reaction, using hybridization probes, is used to detect the verotoxin genes 1 and 2 found in E. coli O157:H7. The assay has a detection limit of log₁₀ 3.5/mL E. coli O157:H7 cells in minced beef.