A team from Purdue University has developed a new assay to detect E. coli O157:H7 in ground beef that claims to shorten the time it takes to get test results, according to a release from the university’s Agricultural Communications department.
Bruce Applegate, professor of food science, led the team that has created the new assay, which saves time by performing crucial steps during shipment of the sample. Enrichment and detection of E. coli occurs during the 15 hours or more needed to send samples from a production facility to an FSIS testing laboratory. Details of the assay were published in the journal Foods.
The system is based on bacteriophage (or phage) technology. After infecting E. coli O157:H7, the phage — which has been genetically modified — produces an enzyme that makes light and causes the infected cells to glow, indicating the presence of the pathogen. The enrichment step, by this time, will have created thousands of copies of the pathogen in the sample from a single specimen — therefore, phage infection should cause the entire culture to glow.
