The use of a fluorescent bacteriophage assay for detection of Escherichia coli O157:H7 in inoculated ground beef and raw milk

Int J Food Microbiol. 1999 Mar 1;47(1-2):43-50. doi: 10.1016/s0168-1605(99)00010-0.

Abstract

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.

MeSH terms

  • Animals
  • Bacteriophage Typing*
  • Benzoxazoles / chemistry
  • Cattle
  • Coliphages / chemistry
  • Escherichia coli Infections / prevention & control
  • Escherichia coli O157 / isolation & purification*
  • Flow Cytometry
  • Fluorescent Dyes / chemistry
  • Food Microbiology*
  • Foodborne Diseases / prevention & control
  • Immunomagnetic Separation
  • Meat / microbiology*
  • Microscopy, Fluorescence
  • Microspheres
  • Milk / microbiology*
  • Quinolinium Compounds / chemistry

Substances

  • Benzoxazoles
  • Fluorescent Dyes
  • Quinolinium Compounds
  • 1,1'-((4,4,7,7-tetramethyl)-4,7-diazaundecamethylene)bis-4-(3-methyl-2,3-dihydro(benzo-1,3-oxazole)-2-methylidene)quinolinium