Inhibition of Escherichia coli O157:H7, Listeria monocytogenes and Staphylococcus aureus on sliced roast beef by cetylpyridinium chloride and acidified sodium chlorite

The effects of selected food-grade antimicrobial agents at decreasing the number of pathogenic bacteria on fresh beef were determined. Beef cubes inoculated with Escherichia coli O157:H7, Listeria monocytogenes, or Staphylococcus aureus were sprayed with 0.5% cetylpyridinium chloride (CPC), 0.12% acidified sodium chlorite (ASC), 0.1% potassium sorbate (PS), or an equal mix of any two solutions. The beef samples were placed on absorbent tray pads sprayed with each single or mixed solution, wrapped with polyvinyl chloride film, heat sealed, and stored at 4°C for 2 weeks. Surface sanitization using CPC, ASC, or an equal mix of these two agents effectively reduced microbial numbers on the beef during storage. At day 0, ASC and the CPC-ASC mix reduced the number of E. coli O157:H7 by 2.50 and 1.58 log CFU/cm2, respectively. CPC demonstrated a 3.25-log reduction of L. monocytogenes and a 4.70-log reduction of S. aureus at 14 days. The CPC-PS mix reduced E. coli O157:H7 numbers by 1.46, L. monocytogenes by 2.95, and S. aureus by 4.41 log CFU/cm2 at 14 days. PS alone and the mixed solutions, CPC-ASC, CPC-PS, or ASC-PS, were not as effective as ASC or CPC alone. To effectively reduce E. coli O157:H7, L. monocytogenes, or S. aureus numbers, higher (>0.1%) concentrations of PS were necessary. Loss of redness and light color of beef surfaces consistently coincided with decreases in pH for ASC-treated beef samples.

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Comparison of Four Commercial DNA Extraction Kits for PCR Detection of Listeria monocytogenes, Salmonella, Escherichia coli O157:H7, and Staphylococcus aureus in Fresh, Minimally Processed Vegetables

Journal of Food Protection ◽

10.4315/0362-028x-71.10.2110 ◽

2008 ◽

Vol 71 (10) ◽

pp. 2110-2114 ◽

Cited By ~ 25

Author(s):

P. ELIZAQUÍVEL ◽

R. AZNAR

Keyword(s):

Escherichia Coli ◽

Staphylococcus Aureus ◽

Listeria Monocytogenes ◽

Dna Extraction ◽

Pcr Detection ◽

Escherichia Coli O157 ◽

Minimally Processed ◽

Green Pepper ◽

Minimally Processed Vegetables ◽

And Staphylococcus Aureus

Four commercial DNA extraction methods, PrepMan Ultra (Applied Biosystems), InstaGene Matrix (BioRad), DNeasy Tissue kit (Qiagen), and UltraClean (MoBio), were tested for PCR detection of Listeria monocytogenes, Escherichia coli O157: H7, Salmonella, and Staphylococcus aureus in fresh, minimally processed vegetables. For comparative purposes, sensitivity assays with specific PCRs were carried out after DNA extraction with the four methods in green pepper, broccoli, and onion artificially inoculated with the four pathogens separately. As confirmed by statistical analysis, the DNeasy Tissue kit rendered the highest sensitivity values in the three matrices assayed for Salmonella, L. monocytogenes, and E. coli O157:H7 and in onion for S. aureus. Despite being the most expensive of the methods compared, the DNeasy Tissue Kit can be successfully applied for any of the four most commonly studied pathogens, thus saving time and overall reducing the cost of the analysis.

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The Effects of a Pickling Process on the Reduction of Escherichia coli O157:H7, Listeria monocytogenes , Salmonella spp. and Staphylococcus aureus Inoculated onto Hard-Cooked Eggs

Journal of Food Safety ◽

10.1111/jfs.12069 ◽

2013 ◽

Vol 33 (4) ◽

pp. 413-417 ◽

Cited By ~ 5

Author(s):

Joshua A. Scheinberg ◽

Wladir B. Valderrama ◽

Catherine N. Cutter

Keyword(s):

Escherichia Coli ◽

Staphylococcus Aureus ◽

Listeria Monocytogenes ◽

Escherichia Coli O157 ◽

Salmonella Spp ◽

Pickling Process ◽

And Staphylococcus Aureus

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Growth of Listeria monocytogenes, Salmonella spp., Escherichia coli O157:H7, and Staphylococcus aureus on Cheese during Extended Storage at 25°C

Journal of Food Protection ◽

10.4315/0362-028x.jfp-14-047 ◽

2014 ◽

Vol 77 (8) ◽

pp. 1275-1288 ◽

Cited By ~ 18

Author(s):

WAN MEI LEONG ◽

RENAE GEIER ◽

SARAH ENGSTROM ◽

STEVE INGHAM ◽

BARBARA INGHAM ◽

...

Keyword(s):

Escherichia Coli ◽

Staphylococcus Aureus ◽

Listeria Monocytogenes ◽

Water Activity ◽

Titratable Acidity ◽

Study Data ◽

Escherichia Coli O157 ◽

Salmonella Spp ◽

Require Time ◽

And Staphylococcus Aureus

Potentially hazardous foods require time/temperature control for safety. According to the U.S. Food and Drug Administration Food Code, most cheeses are potentially hazardous foods based on pH and water activity, and a product assessment is required to evaluate safety of storage >6 h at 21°C. We tested the ability of 67 market cheeses to support growth of Listeria monocytogenes (LM), Salmonella spp. (SALM), Escherichia coli O157:H7 (EC), and Staphylococcus aureus (SA) over 15 days at 25°C. Hard (Asiago and Cheddar), semi-hard (Colby and Havarti), and soft cheeses (mozzarella and Mexican-style), and reduced-sodium or reduced-fat types were tested. Single-pathogen cocktails were prepared and individually inoculated onto cheese slices (~105 CFU/g). Cocktails were 10 strains of L. monocytogenes, 6 of Salmonella spp., or 5 of E. coli O157:H7 or S. aureus. Inoculated slices were vacuum packaged and stored at 25°C for ≤15 days, with surviving inocula enumerated every 3 days. Percent salt-in-the-moisture phase, percent titratable acidity, pH, water activity, and levels of indigenous/starter bacteria were measured. Pathogens did not grow on 53 cheeses, while 14 cheeses supported growth of SA, 6 of SALM, 4 of LM, and 3 of EC. Of the cheeses supporting pathogen growth, all supported growth of SA, ranging from 0.57 to 3.08 log CFU/g (average 1.70 log CFU/g). Growth of SALM, LM, and EC ranged from 1.01 to 3.02 log CFU/g (average 2.05 log CFU/g), 0.60 to 2.68 log CFU/g (average 1.60 log CFU/g), and 0.41 to 2.90 log CFU/g (average 1.69 log CFU/g), respectively. Pathogen growth varied within cheese types or lots. Pathogen growth was influenced by pH and percent salt-in-the-moisture phase, and these two factors were used to establish growth/no-growth boundary conditions for safe, extended storage (≤25°C) of pasteurized milk cheeses. Pathogen growth/no-growth could not be predicted for Swiss-style cheeses, mold-ripened or bacterial surface–ripened cheeses, and cheeses made with nonbovine milk, as insufficient data were gathered. This challenge study data can support science-based decision making in a regulatory framework.

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