A membrane-immunofluorescent-viability staining technique for the detection of Salmonella spp. from fresh and processed meat samples

J Appl Microbiol. 2000 Oct;89(4):587-94. doi: 10.1046/j.1365-2672.2000.01151.x.

Abstract

A direct staining technique was investigated for the detection of viable Salmonella in fresh and processed meats. The technique involved overnight enrichment in BPW, extraction of Salmonella cells onto a polycarbonate membrane, followed by detection of the pathogen using anti-Salmonella monoclonal antibody coupled with an antibody linked-fluorescent stain (Texas Red) and a viability stain (Sytox Green). The technique was applied to the detection of Salm. enteritidis inoculated into broth culture or minced beef and then subjected to a variety of stresses including freezing (- 20 degrees C), heating (2 or 4 min at 56.9 degrees C), low pH (5 or 3.5) or high salt (2 or 4%). The correlation between traditional plate counts and the rapid count varied widely (r2 = 0.98-0.03), depending on the type and level of stress applied to the cells. The reason for the disparity in results obtained, and the potential application of the method as a diagnostic tool, are discussed.

MeSH terms

  • Animals
  • Cattle
  • Chickens
  • Fluorescent Antibody Technique
  • Fluorescent Dyes*
  • Food Handling
  • Freezing
  • Heating
  • Hydrogen-Ion Concentration
  • Meat / microbiology*
  • Organic Chemicals
  • Salmonella enteritidis / growth & development
  • Salmonella enteritidis / immunology
  • Salmonella enteritidis / isolation & purification*
  • Sodium Chloride
  • Staining and Labeling / methods
  • Xanthenes*

Substances

  • Fluorescent Dyes
  • Organic Chemicals
  • SYTOX Green
  • Xanthenes
  • Sodium Chloride
  • Texas red