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.
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.