The use of a fluorescent bacteriophage assay for detection of Escherichia coli O157:H7 in inoculated ground beef and raw milk.
The objective of this study was to develop a fluorescent bacteriophage assay (FBA) for the detection of E. coli O157:H7 in ground beef and raw milk. The FBA is a two step assay that combines immunomagnetic separation, to separate the target organism from mixed culture, with a highly specific fluorescently stained bacteriophage to label the E. coli O157:H7 cells. When used in conjunction with flow cytometry, the FBA was able to detect 2.2 CFU/g of artificially contaminated ground beef following a 6 h enrichment. Between 10(1) and 10(2) CFU/ml of artificially contaminated raw milk were detectable after a 10 h enrichment step. The results show that the FBA is potentially useful as a rapid technique for the preliminary detection of E. coli O157:H7 in food.
Goodridge
L
L
Department of Food Science, University of Guelph, Ontario, Canada.
Chen
J
J
Griffiths
M
M
D000818:Animals; D001434:Bacteriophage Typing; D001583:Benzoxazoles / Q000737:chemistry; D002417:Cattle; D003090:Coliphages / Q000737:chemistry; D004927:Escherichia coli Infections / Q000517:prevention & control; D019453:Escherichia coli O157 / Q000302:isolation & purification*; D005434:Flow Cytometry; D005456:Fluorescent Dyes / Q000737:chemistry; D005516:Food Microbiology; D005517:Foodborne Diseases / Q000517:prevention & control; D018189:Immunomagnetic Separation; D008460:Meat / Q000382:microbiology*; D008856:Microscopy, Fluorescence; D008863:Microspheres; D008892:Milk / Q000382:microbiology*; D011806:Quinolinium Compounds / Q000737:chemistry
D001583:Benzoxazoles; D005456:Fluorescent Dyes; D011806:Quinolinium Compounds; C075296:1,1'-((4,4,7,7-tetramethyl)-4,7-diazaundecamethylene)bis-4-(3-methyl-2,3-dihydro(benzo-1,3-oxazole)-2-methylidene)quinolinium