Antimicrobial Performance of Alkaline Ionic Fluid (GC-100X) and Its Ability To Remove Escherichia coli O157:H7 from the Surface of Tomatoes

2003 ◽  
Vol 66 (9) ◽  
pp. 1604-1610 ◽  
Author(s):  
N. H. KWON ◽  
S. H. KIM ◽  
J. Y. KIM ◽  
J. Y. LIM ◽  
J. M. KIM ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Foodborne Pathogens ◽  
Hard Water ◽  
Viable Cell ◽  
Organic Load ◽  
Korean Isolate ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Cell Counts ◽  
Chlorine Water

An efficacy test of GC-100X, a noncorrosive alkaline ionic fluid (pH 12) composed of free radicals and supplemented with xylitol, was carried out against six major foodborne pathogens—Staphylococcus aureus FRI 913, Salmonella enterica serovar Enteritidis ATCC 13076, S. enterica serovar Typhimurium DT104 Korean isolate, Vibrio parahaemolyticus ATCC 17803, Escherichia coli O157:H7 ATCC 43894, and Pseudomonas aeruginosa KCTC 1637—at three different temperatures (4, 25, and 36°C) with or without organic load (2% yeast extract). Results revealed a more than 4-log10 (CFU/ml) reduction (1.0 × 104 CFU/ml reduction) against all pathogens reacted at 37°C for 3 h in the absence of organic material. GC-100X solution diluted with an equal volume of distilled or standard hard water (300 ppm CaCO3) showed effective bactericidal activity, particularly against gram-negative bacteria. Washing efficacy of GC-100X solution was compared against E. coli O157:H7 on cherry tomato surfaces with those of a commercially used detergent and chlorine water (100 ppm). Viable cell counts of E. coli O157:H7 that had penetrated to the cores of tomatoes after sanitizing treatment revealed that GC-100X stock and its 5% diluted solutions had similar washing effects to 100-ppm chlorine water and were more effective than the other kitchen detergent. These results indicate that GC-100X has good bactericidal and sanitizing activities and is useful as a new sanitizer for food safety and kitchen hygiene.

Antibacterial Effect of Water-Soluble Arrowroot (Puerariae radix) Tea Extracts on Foodborne Pathogens in Ground Beef and Mushroom Soup

2004 ◽  
Vol 67 (9) ◽  
pp. 1953-1956 ◽  
Author(s):  
S. KIM ◽  
D. Y. C. FUNG
Keyword(s):  
Foodborne Pathogens ◽  
Salmonella Enteritidis ◽  
Ground Beef ◽  
Viable Cell ◽  
Water Soluble ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Cell Counts ◽  
Tea Extract ◽  
And Staphylococcus Aureus

Antimicrobial activity of water-soluble arrowroot tea extract was evaluated against Escherichia coli O157:H7, Salmonella enterica Serotype Enteritidis, Listeria monocytogenes, and Staphylococcus aureus in ground beef and mushroom soup. The concentrations of arrowroot tea used were 0, 3, and 6% (wt/wt) for ground beef and 0, 1, 5, and 10% (wt/vol) for mushroom soup. Samples without tea extract were considered controls. Each sample was stored for 0, 1, 3, 5, and 7 days at 7°C for ground beef and for 0, 1, 3, and 5 days at 35°C for mushroom soup. On each sampling time, proper dilutions were spread plated on each pathogen-specific agar. Viable cell counts of each pathogen were performed after incubation at 35°C for 24 to 48 h. For ground beef, Salmonella Enteritidis and L. monocytogenes were slightly suppressed by approximately 1.5 log, compared with the control, on day 7 at 3 and 6% arrowroot tea treatment. For mushroom soup, all test pathogens were suppressed by 6.5, 4.7, 3.4, and 4.3 log at 5% and 6.0, 4.7, 5.0, and 4.3 log at 10% against E. coli O157:H7, Salmonella Enteritidis, L. monocytogenes, and S. aureus, respectively, compared with the control on day 5. Mushroom soup with 1% arrowroot tea also showed 2.3- and 2.7-log growth suppression of Salmonella Enteritidis and S. aureus, respectively, compared with the control on day 5. This study showed that the use of arrowroot tea would effectively inhibit the microbial growth of both gram-negative and gram-positive foodborne pathogens in various foods, especially liquid foods.

Development of an Algorithm for Feed-Forward Chlorine Dosing of Lettuce Wash Operations and Correlation of Chlorine Profile with Escherichia coli O157:H7 Inactivation

2014 ◽  
Vol 77 (4) ◽  
pp. 558-566 ◽  
Author(s):  
BIN ZHOU ◽  
YAGUANG LUO ◽  
XIANGWU NOU ◽  
PATRICIA MILLNER
Keyword(s):  
Escherichia Coli ◽  
Reduction Potential ◽  
Free Chlorine ◽  
Organic Load ◽  
Escherichia Coli O157 ◽  
Feed Forward ◽  
E Coli ◽  
Wash Solution ◽  
Oxidation Reduction ◽  
Oxidation Reduction Potential

The dynamic interactions of chlorine and organic matter during a simulated fresh-cut produce wash process and the consequences for Escherichia coli O157:H7 inactivation were investigated. An algorithm for a chlorine feed-forward dosing scheme to maintain a stable chlorine level was further developed and validated. Organic loads with chemical oxygen demand of 300 to 800 mg/liter were modeled using iceberg lettuce. Sodium hypochlorite (NaOCl) was added to the simulated wash solution incrementally. The solution pH, free and total chlorine, and oxidation-reduction potential were monitored, and chlorination breakpoint and chloramine humps determined. The results indicated that the E. coli O157:H7 inactivation curve mirrored that of the free chlorine during the chlorine replenishment process: a slight reduction in E. coli O157:H7 was observed as the combined chlorine hump was approached, while the E. coli O157:H7 cell populations declined sharply after chlorination passed the chlorine hump and decreased to below the detection limit (<0.75 most probable number per ml) after the chlorination breakpoint was reached. While the amounts of NaOCl required for reaching the chloramine humps and chlorination breakpoints depended on the organic loads, there was a linear correlation between NaOCl input and free chlorine in the wash solution once NaOCl dosing passed the chlorination breakpoint, regardless of organic load. The data obtained were further exploited to develop a NaOCl dosing algorithm for maintaining a stable chlorine concentration in the presence of an increasing organic load. The validation tests results indicated that free chlorine could be maintained at target levels using such an algorithm, while the pH and oxidation-reduction potential were also stably maintained using this system.

scholarly journals Growth of Salmonella and Other Foodborne Pathogens on Inoculated Inshell Pistachios during Simulated Delays between Hulling and Drying

2019 ◽  
Vol 82 (5) ◽  
pp. 815-825 ◽  
Author(s):  
MAHTA MOUSSAVI ◽  
VANESSA LIEBERMAN ◽  
CHRIS THEOFEL ◽  
JAVAD BAROUEI ◽  
LINDA J. HARRIS
Keyword(s):  
Escherichia Coli ◽  
Relative Humidity ◽  
Foodborne Pathogens ◽  
Lag Time ◽  
Escherichia Coli O157 ◽  
Contributing Factors ◽  
Shell Surface ◽  
E Coli ◽  
Significant Growth ◽  
Lower Maximum

ABSTRACT During harvest, pistachios are hulled, separated in water into floater and sinker streams (in large part on the basis of nut density), and then dried before storage. Higher prevalence and levels of Salmonella were previously observed in floater pistachios, but contributing factors are unclear. To examine the behavior of pathogens on hulled pistachios during simulated drying delays, floater and sinker pistachios collected from commercial processors were inoculated at 1 or 3 log CFU/g with cocktails of Salmonella and in some cases Escherichia coli O157:H7 or Listeria monocytogenes and incubated for up to 30 h at 37°C and 90% relative humidity. Populations were measured by plating onto tryptic soy agar and appropriate selective agars. In most cases, no significant growth (P > 0.05) of Salmonella was observed in the first 3 h after inoculation in hulled floaters and sinkers. Growth of Salmonella was greater on floater pistachios than on corresponding sinkers and on floater pistachios with ≥25% hull adhering to the shell surface than on corresponding floaters with <25% adhering hull. Maximum Salmonella populations (2 to 7 log CFU/g) were ∼2-log higher on floaters than on corresponding sinkers. The growth of E. coli O157:H7 and Salmonella on hulled pistachios was similar, but a longer lag time (approximately 11 h) and significantly lower maximum populations (4 versus 5 to 6 log CFU/g; P < 0.05) were predicted for L. monocytogenes. Significant growth of pathogens on hulled pistachios is possible when delays between hulling and drying are longer than 3 h, and pathogen growth is enhanced in the presence of adhering hull material.

Inactivation of Escherichia coli O157:H7 and Salmonella and Native Microbiota on Fresh Strawberries by Antimicrobial Washing and Coating

2018 ◽  
Vol 81 (8) ◽  
pp. 1227-1235 ◽  
Author(s):  
MINGMING GUO ◽  
TONY Z. JIN ◽  
JOSHUA B. GURTLER ◽  
XUETONG FAN ◽  
MADHAV P. YADAV
Keyword(s):  
Escherichia Coli ◽  
Foodborne Pathogens ◽  
Allyl Isothiocyanate ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Native Microflora ◽  
Pathogen Populations ◽  
Antimicrobial Treatments ◽  
Antimicrobial Effectiveness

ABSTRACT Antimicrobial washing (AW), antimicrobial coating (AC), and a combination of washing followed by coating (AW+AC) were evaluated for their ability to inactivate artificially inoculated foodborne pathogens and native microbiota on strawberries stored at 4°C. Strawberries were inoculated with a six-strain composite of Escherichia coli O157:H7 and Salmonella; treated by AW, AC, or AW+AC; and stored at 4°C for 3 weeks. The washing solution contained 90 ppm of peracetic acid, and the coating solution consisted of chitosan (1%, w/v), allyl isothiocyanate (1%, v/v), and corn-bio fiber gum (5%, w/v). The effectiveness of the antimicrobial treatments against E. coli O157:H7 and Salmonella pathogens and native microflora on strawberries and their impact on fruit quality (appearance, weight loss, color, and firmness) were determined. By the end of storage, pathogen populations on strawberries were 2.5 (AW+AC), 2.9 (AC), 3.8 (AW), and 4.2 log CFU for the positive (untreated) control. AW+AC treatments also inactivated the greatest population of native microflora, followed by the AC treatment alone. AW+AC treatments showed additional antimicrobial effectiveness against these two pathogens and native microflora. Both AW+AC and AC treatments preserved the color, texture, and appearance of strawberries throughout storage. The coating treatments (AW+AC and AC alone) further reduced the loss of moisture throughout storage. The AW treatment was the least effective in reducing populations of pathogens and native microflora and in maintaining the quality of strawberries throughout storage. This study demonstrates a method to improve the microbiological safety, shelf life, and quality of strawberries.

Rapid and Sensitive Detection of Escherichia coli O157:H7 in Milk and Ground Beef Using Magnetic Bead–Based Immunoassay Coupled with Tyramide Signal Amplification

2014 ◽  
Vol 77 (1) ◽  
pp. 100-105 ◽  
Author(s):  
MUHSIN AYDIN ◽  
GENE P. D. HERZIG ◽  
KWANG CHEOL JEONG ◽  
SAMANTHA DUNIGAN ◽  
PARTH SHAH ◽  
...  
Keyword(s):  
Public Health ◽  
Escherichia Coli ◽  
Food Safety ◽  
Foodborne Pathogens ◽  
Signal Amplification ◽  
Magnetic Bead ◽  
Escherichia Coli O157 ◽  
Tyramide Signal Amplification ◽  
E Coli ◽  
Enrichment Step

Escherichia coli O157:H7 is a major foodborne pathogen that has posed serious problems for food safety and public health. Recent outbreaks and recalls associated with various foods contaminated by E. coli O157:H7 clearly indicate its deleterious effect on food safety. A rapid and sensitive detection assay is needed for this harmful organism to prevent foodborne illnesses and control outbreaks in a timely manner. We developed a magnetic bead–based immunoassay for detection of E. coli O157:H7 (the most well-known Shiga toxigenic E. coli strain) with a 96-well microplate as an assay platform. Immunomagnetic separation (IMS) and tyramide signal amplification were coupled to the assay to increase its sensitivity and specificity. This immunoassay was able to detect E. coli O157:H7 in pure culture with a detection limit of 50 CFU/ml in less than 3 h without an enrichment step. The detection limit was decreased 10-fold to 5 CFU/ml with addition of a 3-h enrichment step. When this assay was tested with other nontarget foodborne pathogens and common enteric bacteria, no cross-reactivity was found. When tested with artificially contaminated ground beef and milk samples, the assay sensitivity decreased two- to fivefold, with detection limits of 250 and 100 CFU/ml, respectively, probably because of the food matrix effect. The assay results also were compared with those of a sandwich-type enzyme-linked immunosorbent assay (ELISA) and an ELISA coupled with IMS; the developed assay was 25 times and 4 times more sensitive than the standard ELISA and the IMS-ELISA, respectively. Tyramide signal amplification combined with IMS can improve sensitivity and specificity for detection of E. coli O157:H7. The developed assay could be easily adapted for other foodborne pathogens and will contribute to improved food safety and public health.

Inactivation of Escherichia coli O157:H7 and Listeria monocytogenes on Plastic Kitchen Cutting Boards by Electrolyzed Oxidizing Water

1999 ◽  
Vol 62 (8) ◽  
pp. 857-860 ◽  
Author(s):  
KUMAR S. VENKITANARAYANAN ◽  
GABRIEL O. I. EZEIKE ◽  
YEN-CON HUNG ◽  
MICHAEL P. DOYLE
Keyword(s):  
Escherichia Coli ◽  
Listeria Monocytogenes ◽  
Laminar Flow ◽  
Foodborne Pathogens ◽  
Deionized Water ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Laminar Flow Hood ◽  
Cutting Boards ◽  
Temperature Time

One milliliter of culture containing a five-strain mixture of Escherichia coli O157:H7 (∼1010 CFU) was inoculated on a 100-cm2 area marked on unscarred cutting boards. Following inoculation, the boards were air-dried under a laminar flow hood for 1 h, immersed in 2 liters of electrolyzed oxidizing water or sterile deionized water at 23°C or 35°C for 10 or 20 min; 45°C for 5 or 10 min; or 55°C for 5 min. After each temperature–time combination, the surviving population of the pathogen on cutting boards and in soaking water was determined. Soaking of inoculated cutting boards in electrolyzed oxidizing water reduced E. coli O157:H7 populations by ≥5.0 log CFU/100 cm2 on cutting boards. However, immersion of cutting boards in deionized water decreased the pathogen count only by 1.0 to 1.5 log CFU/100 cm2. Treatment of cutting boards inoculated with Listeria monocytogenes in electrolyzed oxidizing water at selected temperature–time combinations (23°C for 20 min, 35°C for 10 min, and 45°C for 10 min) substantially reduced the populations of L. monocytogenes in comparison to the counts recovered from the boards immersed in deionized water. E. coli O157:H7 and L. monocytogenes were not detected in electrolyzed oxidizing water after soaking treatment, whereas the pathogens survived in the deionized water used for soaking the cutting boards. This study revealed that immersion of kitchen cutting boards in electrolyzed oxidizing water could be used as an effective method for inactivating foodborne pathogens on smooth, plastic cutting boards.

scholarly journals Modelling Growth and Decline in a Two-Species Model System: Pathogenic Escherichia coli O157:H7 and Psychrotrophic Spoilage Bacteria in Milk

Foods ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 331 ◽  
Author(s):  
Emiliano J. Quinto ◽  
Juan M. Marín ◽  
Irma Caro ◽  
Javier Mateo ◽  
Donald W. Schaffner
Keyword(s):  
Escherichia Coli ◽  
Foodborne Pathogens ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Food Borne ◽  
Pathogenic Escherichia Coli ◽  
Spoilage Bacteria ◽  
Processing And Storage ◽  
And Storage ◽  
Natural Microbiota

Shiga toxin-producing Escherichia coli O157:H7 is a food-borne pathogen and the major cause of hemorrhagic colitis. Pseudomonas is the genus most frequent psychrotrophic spoilage microorganisms present in milk. Two-species bacterial systems with E. coli O157:H7, non-pathogenic E. coli, and P. fluorescens in skimmed milk at 7, 13, 19, or 25 °C were studied. Bacterial interactions were modelled after applying a Bayesian approach. No direct correlation between P. fluorescens’s growth rate and its effect on the maximum population densities of E. coli species was found. The results show the complexity of the interactions between two species in a food model. The use of natural microbiota members to control foodborne pathogens could be useful to improve food safety during the processing and storage of refrigerated foods.

An Investigation of Escherichia coli O157 Contamination of Cattle during Slaughter at an Abattoir

2005 ◽  
Vol 68 (3) ◽  
pp. 451-457 ◽  
Author(s):  
NARELLE FEGAN ◽  
GLEN HIGGS ◽  
PAUL VANDERLINDE ◽  
PATRICIA DESMARCHELIER
Keyword(s):  
Escherichia Coli ◽  
Oral Cavity ◽  
Immunomagnetic Separation ◽  
Most Probable Number ◽  
Escherichia Coli O157 ◽  
Probable Number ◽  
Fecal Samples ◽  
E Coli ◽  
Cell Counts ◽  
Carcass Contamination

The extent of contamination with Escherichia coli O157 was determined for 100 cattle during slaughter. Samples from 25 consecutively slaughtered cattle from four unrelated groups were collected from the oral cavity, hide, rumen, feces after evisceration, and pre- and postchill carcass. Ten random fecal samples were collected from the pen where each group of animals was held at the abattoir. E. coli O157 was detected using automated immunomagnetic separation (AIMS), and cell counts were determined using a combination of most probable number (MPN) and AIMS. E. coli O157 was isolated from 87 (14%) of the 606 samples collected, including 24% of 99 oral cavity samples, 44% of 100 hides, 10% of 68 fecal samples collected postevisceration, 6% of 100 prechill carcass swabs, and 15% of 40 fecal samples collected from holding pens. E. coli O157 was not isolated from rumen or postchill carcass samples. E. coli O157 was isolated from at least one sample from each group of cattle tested, and the prevalence in different groups ranged from less than 1 to 41%. The numbers of E. coli O157 differed among the animals groups. The group which contained the highest fecal (7.5 × 105 MPN/g) and hide (22 MPN/cm2) counts in any individual animal was the only group in which E. coli O157 was isolated from carcasses, suggesting a link between the numbers of E. coli O157 present and the risk of carcass contamination. Processing practices at this abattoir were adequate for minimizing contamination of carcasses, even when animals were heavily contaminated with E. coli O157.

Synergistic Effect of High Temperature and High pH on the Destruction of Salmonella enteritidis and Escherichia co1i O157:H7

1996 ◽  
Vol 59 (10) ◽  
pp. 1023-1030 ◽  
Author(s):  
YEOW-LIM TEO ◽  
TIMOTHY J. RAYNOR ◽  
KAMESWAR R. ELLAJOSYULA ◽  
STEPHEN J. KNABEL
Keyword(s):  
Escherichia Coli ◽  
High Temperature ◽  
Synergistic Effect ◽  
Foodborne Pathogens ◽  
Salmonella Enteritidis ◽  
Synergistic Interaction ◽  
Escherichia Coli O157 ◽  
Gram Negative ◽  
High Ph ◽  
E Coli

This study was undertaken to determine if high temperature and high pH interact synergistically to enhance the rate of destruction of two important gram-negative foodborne pathogens, Escherichia coli O157:H7 and Salmonella enteritidis. The rates of destruction in NaHCO3-NaOH buffers at pH 7.0, 10.0, and 11.0 were determined at 35, 40, 45, 50, 55, 60, and 65°C. Use of an improved heating protocol eliminated a “tailing effect” at longer exposure times. The present study demonstrated that the combination of high pH and high temperature resulted in a highly significant synergistic interaction (P > F = 0.0001), which caused rapid death of both E. coli O157:H7 and S. enteritidis. This “alka-therm” technology might be used commercially to destroy gram-negative foodborne pathogens on various raw agricultural commodities.

Quantitative Microbial Risk Assessment for Escherichia coli O157:H7 in Fresh-Cut Lettuce

2017 ◽  
Vol 80 (2) ◽  
pp. 302-311 ◽  
Author(s):  
Hao Pang ◽  
Elisabetta Lambertini ◽  
Robert L. Buchanan ◽  
Donald W. Schaffner ◽  
Abani K. Pradhan
Keyword(s):  
Escherichia Coli ◽  
Foodborne Pathogens ◽  
The United States ◽  
Intervention Strategies ◽  
Sensitivity Analyses ◽  
Escherichia Coli O157 ◽  
Baseline Model ◽  
Microbial Risk ◽  
E Coli ◽  
Fresh Cut

ABSTRACT Leafy green vegetables, including lettuce, are recognized as potential vehicles for foodborne pathogens such as Escherichia coli O157:H7. Fresh-cut lettuce is potentially at high risk of causing foodborne illnesses, as it is generally consumed without cooking. Quantitative microbial risk assessments (QMRAs) are gaining more attention as an effective tool to assess and control potential risks associated with foodborne pathogens. This study developed a QMRA model for E. coli O157:H7 in fresh-cut lettuce and evaluated the effects of different potential intervention strategies on the reduction of public health risks. The fresh-cut lettuce production and supply chain was modeled from field production, with both irrigation water and soil as initial contamination sources, to consumption at home. The baseline model (with no interventions) predicted a mean probability of 1 illness per 10 million servings and a mean of 2,160 illness cases per year in the United States. All intervention strategies evaluated (chlorine, ultrasound and organic acid, irradiation, bacteriophage, and consumer washing) significantly reduced the estimated mean number of illness cases when compared with the baseline model prediction (from 11.4- to 17.9-fold reduction). Sensitivity analyses indicated that retail and home storage temperature were the most important factors affecting the predicted number of illness cases. The developed QMRA model provided a framework for estimating risk associated with consumption of E. coli O157:H7–contaminated fresh-cut lettuce and can guide the evaluation and development of intervention strategies aimed at reducing such risk.

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