Fluorogenic assay for rapid detection of Escherichia coli in chilled and frozen foods: collaborative study.
A collaborative study was conducted to compare a proposed LST-MUG method with the AOAC official method for Escherichia coli detection. E. coli produces an enzyme, beta-glucuronidase, which cleaves the substrate, 4-methyl-umbelliferyl-beta-D-glucuronide (MUG), to yield a fluorescent end product. Incorporation of the MUG substrate into lauryl tryptose broth (LST) enables a rapid quantitative method for screening E. coli, which is detected by fluorescence of the medium under longwave UV light. In this collaborative study, 5 food samples, 2 frozen (entree sauce/gravy and dairy topping) and 3 chilled (hamburger, pork sausage, and cheese), were tested for E. coli detection by 17 collaborating laboratories. Results indicate that the LST-MUG method is equal to or better than the current AOAC method for detecting E. coli. The LST-MUG method has been adopted official first action.
Moberg
L J
LJ
General Mills, Inc., James Ford Bell Technical Center, Minneapolis, MN 55427.
Wagner
M K
MK
Kellen
L A
LA
D000818:Animals; D002417:Cattle; D002611:Cheese / Q000032:analysis; D003080:Cold Temperature; D003611:Dairy Products / Q000032:analysis; D004926:Escherichia coli / Q000032:analysis*; D005516:Food Microbiology; D005519:Food Preservation; D007202:Indicators and Reagents; D008460:Meat / Q000032:analysis; D013050:Spectrometry, Fluorescence; D013552:Swine
D007202:Indicators and Reagents