Treatment of Escherichia coli O157:H7 with lactic acid, neutralized electrolyzed oxidizing water and chlorine dioxide followed by growth under sub-optimal conditions of temperature, pH and modified atmosphere

The present study examined the effect of pH-independent acid resistance of Escherichia coli O157:H7 on efficacy of buffered lactic acid to decontaminate chilled beef tissue. A varied level of acid resistance was observed among the 14 strains tested. Eight strains were categorized as acid resistant, four strains as acid sensitive, and two strains demonstrated acid-inducible acid resistance. The survival of an acid-resistant (II/45/4) and acid-sensitive (IX/8/16) E. coli O157:H7 strain on chilled beef tissue treated with 1 and 2% buffered lactic acid, sterile water, or no treatment (control) was followed. A gradual reduction of E. coli O157:H7 was noticed during the 10 days of storage at 4°C for each of the treatments. Decontamination with 1 and 2% buffered lactic acid did not appreciably affect the pathogen. Differences in the pH-independent acid resistance of the strains had no effect on the efficacy of decontamination. The effect of modified atmosphere packaging (MAP) on survival of E. coli O157:H7 in red meat was also studied. MAP (40% CO2/60% N2) or vacuum did not significantly influence survival of E. coli O157:H7 on inoculated sliced beef (retail cuts) meat compared to packing in air. The relative small outgrowth of lactic acid bacteria during storage under vacuum for 28 days did not affect survival of E. coli O157:H7. Neither lactic acid decontamination nor vacuum or MAP packaging could enhance reduction of E. coli O157:H7 on beef, thus underlining the need for preventive measures to control the public health risk of E. coli O157:H7.

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Lactic acid bacteria biofilms and their ability to mitigate Escherichia coli O157:H7 surface colonization

Letters in Applied Microbiology ◽

10.1111/lam.13509 ◽

2021 ◽

Author(s):

L Cisneros ◽

N Cattelan ◽

MI Villalba ◽

C. Rodriguez ◽

DO Serra ◽

...

Keyword(s):

Escherichia Coli ◽

Lactic Acid ◽

Lactic Acid Bacteria ◽

Escherichia Coli O157 ◽

Surface Colonization

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Reduction of Escherichia coli O157:H7 Counts on Whole Fresh Apples by Treatment with Sanitizers

Journal of Food Protection ◽

10.4315/0362-028x-63.6.703 ◽

2000 ◽

Vol 63 (6) ◽

pp. 703-708 ◽

Cited By ~ 65

Author(s):

MARCY A. WISNIEWSKY ◽

BONITA A. GLATZ ◽

MARK L. GLEASON ◽

CHERYLL A. REITMEIER

Keyword(s):

Escherichia Coli ◽

Chlorine Dioxide ◽

Phosphate Buffer ◽

Phosphate Buffer Solution ◽

Escherichia Coli O157 ◽

Peroxyacetic Acid ◽

Water Control ◽

Buffer Solution ◽

E Coli ◽

Log Reduction

The objectives of this study were to determine if washing of whole apples with solutions of three different sanitizers (peroxyacetic acid, chlorine dioxide, or a chlorine-phosphate buffer solution) could reduce a contaminating nonpathogenic Escherichia coli O157:H7 population by 5 logs and at what sanitizer concentration and wash time such a reduction could be achieved. Sanitizers were tested at 1, 2, 4, 8, and 16 times the manufacturer's recommended concentration at wash times of 5, 10, and 15 min. Whole, sound Braeburn apples were inoculated with approximately 1 × 108 or 7 × 106 CFU per apple, stored for 24 h, then washed with sterile water (control) or with sanitizers for the prescribed time. Recovered bacteria were enumerated on trypticase soy agar. Washing with water alone reduced the recoverable population by almost 2 logs from the starting population; this can be attributed to physical removal of organisms from the apple surface. No sanitizer, when used at the recommended concentration, reduced the recovered E. coli population by 5 logs under the test conditions. The most effective sanitizer, peroxyacetic acid, achieved a 5-log reduction when used at 2.1 to 14 times its recommended concentration, depending on the length of the wash time. The chlorine-phosphate buffer solution reduced the population by 5 logs when used at 3 to 15 times its recommended concentration, depending on wash time. At no concentration or wash time tested did chlorine dioxide achieve the 5-log reduction.

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Evaluation of Gaseous Chlorine Dioxide as a Sanitizer for Killing Salmonella, Escherichia coli O157:H7, Listeria monocytogenes, and Yeasts and Molds on Fresh and Fresh-Cut Produce

Journal of Food Protection ◽

10.4315/0362-028x-68.6.1176 ◽

2005 ◽

Vol 68 (6) ◽

pp. 1176-1187 ◽

Cited By ~ 112

Author(s):

KAYE V. SY ◽

MELINDA B. MURRAY ◽

M. DAVID HARRISON ◽

LARRY R. BEUCHAT

Keyword(s):

Escherichia Coli ◽

Listeria Monocytogenes ◽

Chlorine Dioxide ◽

Foodborne Pathogens ◽

Escherichia Coli O157 ◽

Gaseous Chlorine Dioxide ◽

Sensory Qualities ◽

A Cell ◽

Fresh Cut ◽

Yeasts And Molds

Gaseous chlorine dioxide (ClO2) was evaluated for effectiveness in killing Salmonella, Escherichia coli O157:H7, and Listeria monocytogenes on fresh-cut lettuce, cabbage, and carrot and Salmonella, yeasts, and molds on apples, peaches, tomatoes, and onions. Inoculum (100 μl, ca. 6.8 log CFU) containing five serotypes of Salmonella enterica, five strains of E. coli O157:H7, or five strains of L. monocytogenes was deposited on the skin and cut surfaces of fresh-cut vegetables, dried for 30 min at 22°C, held for 20 h at 4°C, and then incubated for 30 min at 22°C before treatment. The skin surfaces of apples, peaches, tomatoes, and onions were inoculated with 100 μl of a cell suspension (ca. 8.0 log CFU) containing five serotypes of Salmonella, and inoculated produce was allowed to dry for 20 to 22 h at 22°C before treatment. Treatment with ClO2 at 4.1 mg/liter significantly (α = 0.05) reduced the population of foodborne pathogens on all produce. Reductions resulting from this treatment were 3.13 to 4.42 log CFU/g for fresh-cut cabbage, 5.15 to 5.88 log CFU/g for fresh-cut carrots, 1.53 to 1.58 log CFU/g for fresh-cut lettuce, 4.21 log CFU per apple, 4.33 log CFU per tomato, 1.94 log CFU per onion, and 3.23 log CFU per peach. The highest reductions in yeast and mold populations resulting from the same treatment were 1.68 log CFU per apple and 2.65 log CFU per peach. Populations of yeasts and molds on tomatoes and onions were not significantly reduced by treatment with 4.1 mg/liter ClO2. Substantial reductions in populations of pathogens on apples, tomatoes, and onions but not peaches or fresh-cut cabbage, carrot, and lettuce were achieved by treatment with gaseous ClO2 without markedly adverse effects on sensory qualities.

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Corrigendum to “Inhibition of in vitro growth of Shiga toxin-producing Escherichia coli O157:H7 by probiotic Lactobacillus strains due to production of lactic acid”[Int. J. Food Microbiol. 68 (2001) 135–140]

International Journal of Food Microbiology ◽

10.1016/s0168-1605(02)00036-3 ◽

2002 ◽

Vol 74 (1-2) ◽

pp. 167

Author(s):

Michinaga Ogawa ◽

Kensuke Shimizu ◽

Koji Nomoto ◽

Ryuichiro Tanaka ◽

Takashi Hamabata ◽

...

Keyword(s):

Escherichia Coli ◽

Lactic Acid ◽

Shiga Toxin ◽

Escherichia Coli O157 ◽

In Vitro Growth ◽

Probiotic Lactobacillus

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Relative gene expression in acid-adapted Escherichia coli O157:H7 during lactoperoxidase and lactic acid challenge in Tryptone Soy Broth

Microbiological Research ◽

10.1016/j.micres.2009.11.003 ◽

2010 ◽

Vol 165 (7) ◽

pp. 546-556 ◽

Cited By ~ 11

Author(s):

Angela A. Parry-Hanson ◽

Piet J. Jooste ◽

Elna M. Buys

Keyword(s):

Gene Expression ◽

Escherichia Coli ◽

Lactic Acid ◽

Escherichia Coli O157 ◽

Relative Gene Expression ◽

Relative Gene ◽

Acid Challenge

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Inactivation of Escherichia coli O157:H7, Salmonella enterica Serotype Enteritidis, and Listeria monocytogenes on Lettuce by Hydrogen Peroxide and Lactic Acid and by Hydrogen Peroxide with Mild Heat

Journal of Food Protection ◽

10.4315/0362-028x-65.8.1215 ◽

2002 ◽

Vol 65 (8) ◽

pp. 1215-1220 ◽

Cited By ~ 107

Author(s):

CHIA-MIN LIN ◽

SARAH S. MOON ◽

MICHAEL P. DOYLE ◽

KAY H. McWATTERS

Keyword(s):

Escherichia Coli ◽

Hydrogen Peroxide ◽

Lactic Acid ◽

Listeria Monocytogenes ◽

Salmonella Enterica ◽

Salmonella Enteritidis ◽

Sensory Characteristics ◽

Escherichia Coli O157 ◽

E Coli ◽

Log Reduction

Iceberg lettuce is a major component in vegetable salad and has been associated with many outbreaks of foodborne illnesses. In this study, several combinations of lactic acid and hydrogen peroxide were tested to obtain effective antibacterial activity without adverse effects on sensory characteristics. A five-strain mixture of Escherichia coli O157:H7, Salmonella enterica serotype Enteritidis, and Listeria monocytogenes was inoculated separately onto fresh-cut lettuce leaves, which were later treated with 1.5% lactic acid plus 1.5% hydrogen peroxide (H2O2) at 40°C for 15 min, 1.5% lactic acid plus 2% H2O2 at 22°C for 5 min, and 2% H2O2 at 50°C for 60 or 90 s. Control lettuce leaves were treated with deionized water under the same conditions. A 4-log reduction was obtained for lettuce treated with the combinations of lactic acid and H2O2 for E. coli O157:H7 and Salmonella Enteritidis, and a 3-log reduction was obtained for L. monocytogenes. However, the sensory characteristics of lettuce were compromised by these treatments. The treatment of lettuce leaves with 2% H2O2 at 50°C was effective not only in reducing pathogenic bacteria but also in maintaining good sensory quality for up to 15 days. A ≤4-log reduction of E. coli O157:H7 and Salmonella Enteritidis was achieved with the 2% H2O2 treatment, whereas a 3-log reduction of L. monocytogenes was obtained. There was no significant difference (P > 0.05) between pathogen population reductions obtained with 2% H2O2 with 60- and 90-s exposure times. Hydrogen peroxide residue was undetectable (the minimum level of sensitivity was 2 ppm) on lettuce surfaces after the treated lettuce was rinsed with cold water and centrifuged with a salad spinner. Hence, the treatment of lettuce with 2% H2O2 at 50°C for 60 s is effective in initially reducing substantial populations of foodborne pathogens and maintaining high product quality.

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