Combined treatment with silver ions and organic acid enhances growth-inhibition of Escherichia coli O157:H7

Food Control ◽  
2007 ◽  
Vol 18 (10) ◽  
pp. 1235-1240 ◽  
Author(s):  
Seong-Chun Jo ◽  
A-Ram Rim ◽  
Hee-Jin Park ◽  
Hyun-Gyun Yuk ◽  
Seung-Cheol Lee
Keyword(s):  
Escherichia Coli ◽  
Growth Inhibition ◽  
Organic Acid ◽  
Combined Treatment ◽  
Silver Ions ◽  
Escherichia Coli O157

Growth Inhibition of Escherichia coli O157:H7 and Listeria monocytogenes by Carvacrol and Eugenol Encapsulated in Surfactant Micelles

2005 ◽  
Vol 68 (12) ◽  
pp. 2559-2566 ◽  
Author(s):  
SYLVIA GAYSINSKY ◽  
P. MICHAEL DAVIDSON ◽  
BARRY D. BRUCE ◽  
JOCHEN WEISS
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Activity ◽  
Listeria Monocytogenes ◽  
Essential Oil ◽  
Growth Inhibition ◽  
Surfactant Concentration ◽  
Escherichia Coli O157 ◽  
Surfactant Micelles ◽  
E Coli ◽  
Oil Components

Growth inhibition of four strains of Escherichia coli O157:H7 (H1730, F4546, 932, and E0019) and Listeria monocytogenes (Scott A, 101, 108, and 310) by essential oil components (carvacrol and eugenol) solubilized in nonionic surfactant micelles (Surfynol 465 and 485W) was investigated. Concentrations of encapsulated essential oil components ranged from 0.02 to 1.25% depending on compound, surfactant type, and surfactant concentration (0.5 to 5%). Eugenol encapsulated in Surfynol 485W micelles was most efficient in inhibiting growth of the pathogens; 1% Surfynol 485W and 0.15% eugenol was sufficient to inhibit growth of all strains of E. coli O157:H7 and three of four strains of L. monocytogenes (Scott A, 310, and 108). The fourth strain, L. monocytogenes 101, was inhibited by 2.5% Surfynol and 0.225% eugenol. One percent Surfynol 485W in combination with 0.025% carvacrol was effective in inhibiting three of four strains of E. coli O157:H7. Strain H1730 was the most resistant strain, requiring 0.3% carvacrol and 5% surfactant for complete inhibition. Growth inhibition of L. monocytogenes by combinations of carvacrol and Surfynol 465 ranged between 0.15 and 0.35% and 1 and 3.75%, respectively. Generally, the antimicrobial activity of Surfynol 465 in combination with eugenol was higher than that for the combination with carvacrol. The potent activity was attributed to increased solubility of essential oil components in the aqueous phase due to the presence of surfactants and improved interactions of antimicrobials with microorganisms.

Inactivation of Escherichia coli O157:H7, Salmonella and Listeria monocytogenes by Organic Acid

2007 ◽  
Vol 33 (5) ◽  
pp. 403-407 ◽  
Author(s):  
Jae-Seon Jang ◽  
Hye-Jeong Lee ◽  
Bo-Young Oh ◽  
Jea-Mann Lee ◽  
Jong-Myeong Go ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Listeria Monocytogenes ◽  
Organic Acid ◽  
Escherichia Coli O157

scholarly journals Synergetic Inactivation Mechanism of Protocatechuic Acid and High Hydrostatic Pressure against Escherichia coli O157:H7

Foods ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 3053
Author(s):  
Jingyi Hao ◽  
Yuqing Lei ◽  
Zhilin Gan ◽  
Wanbin Zhao ◽  
Junyan Shi ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Hydrostatic Pressure ◽  
High Hydrostatic Pressure ◽  
Protocatechuic Acid ◽  
Combined Treatment ◽  
Membrane Integrity ◽  
Escherichia Coli O157 ◽  
Safety Issues ◽  
Bactericidal Effects ◽  
The Individual

With the wide application of high hydrostatic pressure (HHP) technology in the food industry, safety issues regarding food products, resulting in potential food safety hazards, have arisen. To address such problems, this study explored the synergetic bactericidal effects and mechanisms of protocatechuic acid (PCA) and HHP against Escherichia coli O157:H7. At greater than 200 MPa, PCA (1.25 mg/mL for 60 min) plus HHP treatments had significant synergetic bactericidal effects that positively correlated with pressure. After a combined treatment at 500 MPa for 5 min, an approximate 9.0 log CFU/mL colony decline occurred, whereas the individual HHP and PCA treatments caused 4.48 and 1.06 log CFU/mL colony decreases, respectively. Mechanistically, membrane integrity and morphology were damaged, and the permeability increased when E. coli O157: H7 was exposed to the synergetic stress of PCA plus HHP. Inside cells, the synergetic treatment additionally targeted the activities of enzymes such as superoxide dismutase, catalase and ATPase, which were inhibited significantly (p ≤ 0.05) when exposed to high pressure. Moreover, an analysis of circular dichroism spectra indicated that the synergetic treatment caused a change in DNA structure, which was expressed as the redshift of the characteristic absorption peak. Thus, the synergetic treatment of PCA plus HHP may be used as a decontamination method owing to the good bactericidal effects on multiple targets.

Efficacy of UV, Acidified Sodium Hypochlorite, and Mild Heat for Decontamination of Surface and Infiltrated Escherichia coli O157:H7 on Green Onions and Baby Spinach

2012 ◽  
Vol 75 (7) ◽  
pp. 1198-1206 ◽  
Author(s):  
M. ZEKI DURAK ◽  
JOHN J. CHUREY ◽  
RANDY W. WOROBO
Keyword(s):  
Escherichia Coli ◽  
Sodium Hypochlorite ◽  
Fresh Produce ◽  
Combined Treatment ◽  
Heat Treatments ◽  
Contamination Level ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Mild Heat ◽  
The Individual

Produce-associated foodborne illnesses outbreaks have highlighted the need for more effective decontamination methods to ensure the safety of fresh produce. The main objective of this study was to evaluate the individual and combined efficacies of germicidal UV light (12.5 to 500 mJ/cm2), acidified sodium hypochlorite (ASC; 10 to 200 ppm), and mild heat (40 to 50°C) for decontaminating green onions and baby spinach infected with Escherichia coli O157:H7. Samples were inoculated by spot and dip inoculation methods to mimic surface and infiltrated E. coli O157:H7 contamination, respectively. In green onions and baby spinach, the individual efficacies of UV, ASC, and mild-heat treatments varied based on the produce type and contamination method. Following analysis of the efficacies of the single treatments, a combined treatment with 125 mJ/cm2 UV and 200 ppm of ASC at 50°C was selected for spot-inoculated green onions, and a combined treatment with 125 mJ/cm2 UV and 200 ppm of ASC at 20°C was selected for spot- and dip-inoculated baby spinach. While a >5-log reduction was achieved with the combination treatment for spot-inoculated green onions with an initial contamination level of 7.2 log CFU per spot, the same treatment reduced E. coli O157:H7 populations below the detection limit (<1 log) on green onions spot inoculated at a lower contamination level (4.3 log CFU per spot). On spot- and dip-inoculated baby spinach, the combined treatment reduced E. coli O157:H7 populations by 2.8 log CFU per spot and 2.6 log CFU/g, respectively. The combined treatment of 500 mJ/cm2 UV and 200 ppm of ASC at 50°C selected for the decontamination of dip-inoculated green onions resulted in a 2.2-log CFU/g reduction. These findings suggest that when foodborne pathogens contaminate produce and subsequently infiltrate, attach to, or become localized into protected areas, the individual or combined applications of UV, ASC, and mild-heat treatments have limited decontamination efficacies on both green onions and baby spinach (<3 log). However, treatments combining UV, ASC, and mild heat could be a promising application for reducing pathogen populations (>5 log) on E. coli O157:H7 surface-contaminated green onions. This study also highlights the importance of developing and optimizing produce-specific decontamination methods to ensure the safety of fresh produce commodities.

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