Elution, Detection, and Quantification of Polio I, Bacteriophages, Salmonella Montevideo, and Escherichia coli O157:H7 from Seeded Strawberries and Tomatoes
Authors: Lukasik J.1; Bradley M.L.2; Scott T.M.3; Hsu W-Y.4; Farrah S.R.3; Tamplin M.L.5
Source: Journal of Food Protection®, Volume 64, Number 3, 1 March 2001 , pp. 292-297(6)
Abstract:
This study compared the effect of different physical and chemical treatments of strawberries and tomatoes to determine their ability to recover seeded viral and bacterial pathogens from produce surfaces. Solutions of salts, amino acids, complex media, and detergents were compared as eluants. Phosphate-buffered saline (PBS) containing 0.1% Tween 80 eluted the highest number of seeded microorganisms. Elution with this defined solution was then compared under different conditions of physical agitation. Rotary shaking for 20 min at 36°C eluted higher numbers of viruses and bacteria than did low- or high-speed stomaching. Commercially available and laboratory prepared bacteriological differential media were compared for their ability to recover and distinguish eluted Salmonella Montevideo and Escherichia coli O157:H7 strains from seeded produce. The recovery of seeded bacterial pathogens was low when differential media containing selective ingredients were used (MacConkey sorbitol agar, XLD agar, MacConkey agar). Highest recoveries were obtained on a medium consisting of tryptic soy agar supplemented with sodium thiosulfate and ferric ammonium citrate compared with selective media that inhibited up to 50% of the growth of the eluted microorganisms.Document Type: Research article
Affiliations: 1: Department of Microbiology and Cell Science, Institute for Food and Agricultural Sciences, University of Florida, Gainsville, Florida 32611, USA 2: Department of Food Science and Human Nutrition, University of Florida, Gainsville, Florida 32611, USA 3: Department of Microbiology and Cell Science, University of Florida, Gainsville, Florida 32611, USA 4: Department of Family Youth and Community Science, Institute for Food and Agricultural Sciences, University of Florida, Gainesville, Florida 32611, USA 5: Department of Microbiology and Cell Science, Institute for Food and Agricultural Sciences, University of Florida, Gainesville, Florida 32611, USA

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