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.

scholarly journals Inactivation of Escherichia coli O157:H7 by High Hydrostatic Pressure Combined with Gas Packaging

2019 ◽  
Vol 7 (6) ◽  
pp. 154 ◽  
Author(s):  
Bing Zhou ◽  
Luyao Zhang ◽  
Xiao Wang ◽  
Peng Dong ◽  
Xiaosong Hu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Escherichia Coli ◽  
Hydrostatic Pressure ◽  
High Hydrostatic Pressure ◽  
Cellular Structure ◽  
Combined Treatment ◽  
Physiological Saline ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Significant Difference

The inactivation of Escherichia coli O157:H7 (E. coli) in physiological saline and lotus roots by high hydrostatic pressure (HHP) in combination with CO2 or N2 was studied. Changes in the morphology, cellular structure, and membrane permeability of the cells in physiological saline after treatments were investigated using scanning electron microscopy, transmission electron microscopy, and flow cytometry, respectively. It was shown that after HHP treatments at 150–550 MPa, CO2-packed E. coli cells had higher inactivation than the N2-packed and vacuum-packed cells, and no significant difference was observed in the latter two groups. Further, both the morphology and intracellular structure of CO2-packed E.coli cells were strongly destroyed by high hydrostatic pressure. However, serious damage to the intracellular structures occurred in only the N2-packed E. coli cells. During HHP treatments, the presence of CO2 caused more disruptions in the membrane of E. coli cells than in the N2-packed and vacuum-packed cells. These results indicate that the combined treatment of HHP and CO2 had a strong synergistic bactericidal effect, whereas N2 did not have synergistic effects with HHP. Although these two combined treatments had different effects on the inactivation of E. coli cells, the inactivation mechanisms might be similar. During both treatments, E. coli cells were inactivated by cell damage induced to the cellular structure through the membrane components and the extracellular morphology, unlike the independent HHP treatment.

Loss of cAMP/CRP regulation confers extreme high hydrostatic pressure resistance in Escherichia coli O157:H7

2013 ◽  
Vol 166 (1) ◽  
pp. 65-71 ◽  
Author(s):  
Dietrich Vanlint ◽  
Brecht J.Y. Pype ◽  
Nele Rutten ◽  
Kristof G.A. Vanoirbeek ◽  
Chris W. Michiels ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Hydrostatic Pressure ◽  
High Hydrostatic Pressure ◽  
Escherichia Coli O157 ◽  
Pressure Resistance

scholarly journals Inactivation of Escherichia coli andListeria innocua in Milk by Combined Treatment with High Hydrostatic Pressure and the Lactoperoxidase System

2000 ◽  
Vol 66 (10) ◽  
pp. 4173-4179 ◽  
Author(s):  
Cristina García-Graells ◽  
Caroline Valckx ◽  
Chris W. Michiels
Keyword(s):  
Escherichia Coli ◽  
High Pressure ◽  
Hydrostatic Pressure ◽  
High Hydrostatic Pressure ◽  
Combined Treatment ◽  
Food Preservation ◽  
Pressure Treatment ◽  
E Coli ◽  
Preservation Method ◽  
Lactoperoxidase System

ABSTRACT We have studied inactivation of four strains each ofEscherichia coli and Listeria innocua in milk by the combined use of high hydrostatic pressure and the lactoperoxidase-thiocyanate-hydrogen peroxide system as a potential mild food preservation method. The lactoperoxidase system alone exerted a bacteriostatic effect on both species for at least 24 h at room temperature, but none of the strains was inactivated. Upon high-pressure treatment in the presence of the lactoperoxidase system, different results were obtained for E. coli and L. innocua. For none of the E. coli strains did the lactoperoxidase system increase the inactivation compared to a treatment with high pressure alone. However, a strong synergistic interaction of both treatments was observed for L. innocua. Inactivation exceeding 7 decades was achieved for all strains with a mild treatment (400 MPa, 15 min, 20°C), which in the absence of the lactoperoxidase system caused only 2 to 5 decades of inactivation depending on the strain. Milk as a substrate was found to have a considerable effect protecting E. coli and L. innocua against pressure inactivation and reducing the effectiveness of the lactoperoxidase system under pressure on L. innocua. Time course experiments showed that L. innocua counts continued to decrease in the first hours after pressure treatment in the presence of the lactoperoxidase system.E. coli counts remained constant for at least 24 h, except after treatment at the highest pressure level (600 MPa, 15 min, 20°C), in which case, in the presence of the lactoperoxidase system, a transient decrease was observed, indicating sublethal injury rather than true inactivation.

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