Effect of Anolyte on Background Microflora, Salmonella, and Listeria monocytogenes on Catfish Fillets†

2012 ◽  
Vol 75 (4) ◽  
pp. 765-770 ◽  
Author(s):  
KATHLEEN T. RAJKOWSKI ◽  
CHRISTOPHER H. SOMMERS
Keyword(s):  
Listeria Monocytogenes ◽  
Hypochlorous Acid ◽  
Cellular Membrane ◽  
Residual Chlorine ◽  
Transmission Electron Micrograph ◽  
Bacterial Reduction ◽  
Electrolyzed Water ◽  
Log Reduction ◽  
Catfish Fillets ◽  
Electrolyzing Cell

Near-neutral electrolyzed water (anolyte), having a pH of 6.0 to 6.5 ± 0.02, oxidation reduction potential of greater than 700 mV, and a residual chlorine level of 10 to 200 ppm, was reported to have a potential use to decontaminate food surfaces. An electrolyzing cell was developed that is capable of producing neutral electrolyzed water containing a chlorine level of greater than 700 ppm in the form of hypochlorous acid (anolyte). Anolyte with a chlorine level of 300 ppm was used to determine its effect on Salmonella and Listeria monocytogenes cells after a 3-min contact. Transmission electron micrograph results showed disruption of the outer cellular membrane for both bacteria. The anolyte (300 ppm) was used as a washing solution to decontaminate catfish fillets inoculated with either Salmonella or L. monocytogenes. After a 3-min contact time with the anolyte, there was a 1-log reduction for Salmonella, and after 8 days of refrigerated storage (4°C), this bacterial reduction was maintained. There was no reduction of L. monocytogenes on the catfish fillet surfaces. The anolyte was an effective wash solution for Salmonella reduction on the catfish fillet surfaces.

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

2002 ◽  
Vol 65 (8) ◽  
pp. 1215-1220 ◽  
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.

Power Ultrasound Treatment of Listeria monocytogenes in Apple Cider

2005 ◽  
Vol 68 (11) ◽  
pp. 2333-2340 ◽  
Author(s):  
ADAM R. BAUMANN ◽  
SCOTT E. MARTIN ◽  
HAO FENG
Keyword(s):  
Listeria Monocytogenes ◽  
Saline Solution ◽  
Bactericidal Effect ◽  
Solution Ph ◽  
Power Ultrasound ◽  
Apple Cider ◽  
Log Reduction ◽  
Lethal Temperatures ◽  
First Order Kinetics ◽  
Effects Of Temperature

Inactivation experiments with Listeria monocytogenes 10403S, an ultrasound-resistant strain, were conducted at sublethal (20, 30, and 40°C) and lethal (50, 55, and 60°C) temperatures in saline solution (pH 7.0), acidified saline solution (pH 3.4), and apple cider (pH 3.4) with and without application of ultrasound (20 kHz, 457 mW·ml−1). The survival of recoverable L. monocytogenes 10403S in apple cider was evaluated, and the effects of temperature, ultrasound, pH, and food matrix on inactivation were studied. Application of ultrasound increased the inactivation rate at both sublethal and lethal temperatures. Additional death of L. monocytogenes 10403S was due to low acidity at the lethal temperatures. The reduction in surviving L. monocytogenes 10403S followed first order kinetics at sublethal temperatures, but at lethal temperatures, a two-section linear model described the inactivation behavior. The bactericidal effect of thermosonication was additive in apple cider. The survival tests of L. monocytogenes 10403S in apple cider indicated the possibility of using a mild treatment condition in combination with ultrasound to achieve a 5-log reduction in number of listerial cells.

Effect of Oxygen Stress on Growth and Survival of Clostridium perfringens, Campylobacter jejuni, and Listeria monocytogenes under Different Storage Conditions

2015 ◽  
Vol 78 (4) ◽  
pp. 691-697 ◽  
Author(s):  
HAMZAH AL-QADIRI ◽  
SHYAM S. SABLANI ◽  
MAHMOUDREZA OVISSIPOUR ◽  
NIVIN AL-ALAMI ◽  
BYJU GOVINDAN ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Campylobacter Jejuni ◽  
Clostridium Perfringens ◽  
Foodborne Pathogens ◽  
Storage Conditions ◽  
Growth And Survival ◽  
Anoxic Conditions ◽  
Initial Inoculum ◽  
Log Reduction ◽  
Packaged Food

This study investigated the growth and survival of three foodborne pathogens (Clostridium perfringens, Campylobacter jejuni, and Listeria monocytogenes) in beef (7% fat) and nutrient broth under different oxygen levels. Samples were tested under anoxic (<0.5%), microoxic (6 to 8%), and oxic (20%) conditions during storage at 7°C for 14 days and at 22°C for 5 days. Two initial inoculum concentrations were used (1 and 2 log CFU per g of beef or per ml of broth). The results show that C. perfringens could grow in beef at 22°C, with an increase of approximately 5 log under anoxic conditions and a 1-log increase under microoxic conditions. However, C. perfringens could not survive in beef held at 7°C under microoxic and oxic storage conditions after 14 days. In an anoxic environment, C. perfringens survived in beef samples held at 7°C, with a 1-log reduction. A cell decline was observed at 2 log under these conditions, with no surviving cells at the 1-log level. However, the results show that C. jejuni under microoxic conditions survived with declining cell numbers. Significant increases in L. monocytogenes (5 to 7 log) were observed in beef held at 22°C for 5 days, with the lowest levels recovered under anoxic conditions. L. monocytogenes in refrigerated storage increased by a factor of 2 to 4 log. It showed the greatest growth under oxic conditions, with significant growth under anoxic conditions. These findings can be used to enhance food safety in vacuum-packed and modified atmosphere–packaged food products.

Evaluation of biofilm-forming abilities of Listeria monocytogenes (ATCC 19115) and efficacy of different washing methods for removal of biofilm on apple

Food Research ◽  
2021 ◽  
Vol 5 (4) ◽  
pp. 259-265
Author(s):  
Y. Ali ◽  
H.Y. Mah ◽  
E.T. Phuah ◽  
S.N. Chen ◽  
S.K. Yeo ◽  
...  
Keyword(s):  
Supply Chain ◽  
Listeria Monocytogenes ◽  
Biofilm Formation ◽  
Time Course ◽  
Tap Water ◽  
Fresh Produce ◽  
Foodborne Illness ◽  
Food Supply Chain ◽  
Log Reduction ◽  
Crystal Violet Assay

Fresh produce can be contaminated at any stage along the food supply chain. In this study, apple was chosen to determine the time course of biofilm formation by Listeria monocytogenes (ATCC 19115), as well as to compare the efficacy of different household washing methods such as scrubbing with hands under running tap water, soaking with and without commercial vegetable wash with different treatment times in removing the biofilm formation by L. monocytogenes on apple surface. The biofilm formation was quantified using crystal violet assay and the result showed that L. monocytogenes took 18 hrs to form matured biofilm on apple surface. Besides, scrubbing apples with hands under running tap water for 30 s and 60 s were the most effective method which significantly removed (P<0.05) biofilm formed on the apple surface with approximately 5.93 log reduction. Soaking apples with vegetable wash for 5 mins and 10 mins were also found to be significantly effective (P<0.05) in reducing L. monocytogenes biofilm. Since L. monocytogenes can form matured biofilm on fresh produce, therefore efficient washing step is important before consuming fresh produce to lower the risk of foodborne illness.

scholarly journals The Dynll1-Cox4i1 Complex Regulates Intracellular Pathogen Clearance via Release of Mitochondrial Reactive Oxygen Species

2020 ◽  
Vol 88 (4) ◽  
Author(s):  
Jiangbei Yuan ◽  
Zihan Zheng ◽  
Liting Wang ◽  
Haiying Ran ◽  
Xiangyu Tang ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Listeria Monocytogenes ◽  
Membrane Proteins ◽  
Defense Mechanisms ◽  
Reactive Oxygen ◽  
Cellular Membrane ◽  
Oxygen Species ◽  
Dynein Light Chain ◽  
Mitochondrial Reactive Oxygen Species ◽  
Content Type

ABSTRACT Cellular membrane proteins are a critical part of the host defense mechanisms against infection and intracellular survival of Listeria monocytogenes. The complex spatiotemporal regulation of bacterial infection by various membrane proteins has been challenging to study. Here, using mass spectrometry analyses, we depicted the dynamic expression landscape of membrane proteins upon L. monocytogenes infection in dendritic cells. We showed that Dynein light chain 1 (Dynll1) formed a persistent complex with the mitochondrial cytochrome oxidase Cox4i1, which is disturbed by pathogen insult. We discovered that the dissociation of the Dynll1-Cox4i1 complex is required for the release of mitochondrial reactive oxygen species and serves as a regulator of intracellular proliferation of Listeria monocytogenes. Our study shows that Dynll1 is an inhibitor of mitochondrial reactive oxygen species and can serve as a potential molecular drug target for antibacterial treatment.

scholarly journals A novel antimicrobial coating to prevent periprosthetic joint infection

2020 ◽  
Vol 9 (12) ◽  
pp. 848-856
Author(s):  
Rita Ramalhete ◽  
Robyn Brown ◽  
Gordon Blunn ◽  
John Skinner ◽  
Melanie Coathup ◽  
...  
Keyword(s):  
Stem Cells ◽  
Periprosthetic Joint Infection ◽  
Biofilm Formation ◽  
Autologous Blood ◽  
Joint Infection ◽  
In Vivo Studies ◽  
Dependent Manner ◽  
Bacterial Reduction ◽  
Log Reduction ◽  
Antimicrobial Coating

Aims Periprosthetic joint infection (PJI) is a debilitating condition with a substantial socioeconomic burden. A novel autologous blood glue (ABG) has been developed, which can be prepared during surgery and sprayed onto prostheses at the time of implantation. The ABG can potentially provide an antimicrobial coating which will be effective in preventing PJI, not only by providing a physical barrier but also by eluting a well-known antibiotic. Hence, this study aimed to assess the antimicrobial effectiveness of ABG when impregnated with gentamicin and stem cells. Methods Gentamicin elution from the ABG matrix was analyzed and quantified in a time-dependent manner. The combined efficiency of gentamicin and ABG as an anti-biofilm coating was investigated on titanium disks. Results ABG-gentamicin was bactericidal from 10 μg/ml and could release bactericidal concentrations over seven days, preventing biofilm formation. A concentration of 75 μg/ml of gentamicin in ABG showed the highest bactericidal effect up to day 7. On titanium disks, a significant bacterial reduction on ABG-gentamicin coated disks was observed when compared to both uncoated (mean 2-log reduction) and ABG-coated (mean 3-log reduction) disks, at days 3 and 7. ABG alone exhibited no antimicrobial or anti-biofilm properties. However, a concentration of 75 μg/ml gentamicin in ABG sustains release over seven days and significantly reduced biofilm formation. Its use as an implant coating in patients with a high risk of infection may prevent bacterial adhesion perioperatively and in the early postoperative period. Conclusion ABG’s use as a carrier for stem cells was effective, as it supported cell growth. It has the potential to co-deliver compatible cells, drugs, and growth factors. However, ABG-gentamicin’s potential needs to be further justified using in vivo studies. Cite this article: Bone Joint Res 2020;9(12):848–856.

Determination of the Thermal Inactivation Kinetics of Listeria monocytogenes, Salmonella enterica, and Escherichia coli O157:H7 and non-O157 in Buffer and a Spinach Homogenate

2015 ◽  
Vol 78 (8) ◽  
pp. 1467-1471 ◽  
Author(s):  
EMEFA ANGELICA MONU ◽  
MALCOND VALLADARES ◽  
DORIS H. D'SOUZA ◽  
P. MICHAEL DAVIDSON
Keyword(s):  
Escherichia Coli ◽  
Listeria Monocytogenes ◽  
Salmonella Enterica ◽  
Thermal Inactivation ◽  
Inactivation Kinetics ◽  
Mild Heat ◽  
Log Reduction ◽  
D Values ◽  
Heat Processes ◽  
Kinetics Of

Produce has been associated with a rising number of foodborne illness outbreaks. While much produce is consumed raw, some is treated with mild heat, such as blanching or cooking. The objectives of this research were to compare the thermal inactivation kinetics of Listeria monocytogenes, Salmonella enterica, Shiga toxin–producing Escherichia coli (STEC) O157:H7, and non-O157 STEC in phosphate-buffered saline (PBS; pH 7.2) and a spinach homogenate and to provide an estimate of the safety of mild heat processes for spinach. Five individual strains of S. enterica, L. monocytogenes, STEC O157:H7, and non-O157 STEC were tested in PBS in 2-ml glass vials, and cocktails of the organisms were tested in blended spinach in vacuum-sealed bags. For Listeria and Salmonella at 56 to 60°C, D-values in PBS ranged from 4.42 ± 0.94 to 0.35 ± 0.03 min and 2.11 ± 0.14 to 0.16 ± 0.03 min, respectively. D-values at 54 to 58°C were 5.18 ± 0.21 to 0.53 ± 0.04 min for STEC O157:H7 and 5.01 ± 0.60 to 0.60 ± 0.13 min for non-O157 STEC. In spinach at 56 to 60°C, Listeria D-values were 11.77 ± 2.18 to 1.22 ± 0.12 min and Salmonella D-values were 3.51 ± 0.06 to 0.47 ± 0.06 min. D-values for STEC O157:H7 and non-O157 STEC were 7.21 ± 0.17 to 1.07 ± 0.11 min and 5.57 ± 0.38 to 0.99 ± 0.07 min, respectively, at 56 to 60°C. In spinach, z-values were 4.07 ± 0.16, 4.59 ± 0.26, 4.80 ± 0.92, and 5.22 ± 0.20°C for Listeria, Salmonella, STEC O157:H7, and non-O157 STEC, respectively. Results indicated that a mild thermal treatment of blended spinach at 70°C for less than 1 min would result in a 6-log reduction of all pathogens tested. These findings may assist the food industry in the design of suitable mild thermal processes to ensure food safety.

Inactivation of Escherichia coli O157:H7, Listeria monocytogenes, and Salmonella in Cranberry, Lemon, and Lime Juice Concentrates

2003 ◽  
Vol 66 (9) ◽  
pp. 1637-1641 ◽  
Author(s):  
MARA C. L. NOGUEIRA ◽  
OMAR A. OYARZÁBAL ◽  
DAVID E. GOMBAS
Keyword(s):  
Escherichia Coli ◽  
Listeria Monocytogenes ◽  
Pathogenic Bacteria ◽  
Antimicrobial Properties ◽  
Escherichia Coli O157 ◽  
Bacterial Inactivation ◽  
Lime Juice ◽  
E Coli ◽  
Log Reduction ◽  
C 32

The production of thermally concentrated fruit juices uses temperatures high enough to achieve at least a 5-log reduction of pathogenic bacteria that can occur in raw juice. However, the transportation and storage of concentrates at low temperatures prior to final packaging is a common practice in the juice industry and introduces a potential risk for postconcentration contamination with pathogenic bacteria. The present study was undertaken to evaluate the likelihood of Escherichia coli O157: H7, Listeria monocytogenes and Salmonella surviving in cranberry, lemon, and lime juice concentrates at or above temperatures commonly used for transportation or storage of these concentrates. This study demonstrates that cranberry, lemon, and lime juice concentrates possess intrinsic antimicrobial properties that will eliminate these bacterial pathogens in the event of postconcentration recontamination. Bacterial inactivation was demonstrated under all conditions; at least 5-log Salmonella inactivation was consistently demonstrated at −23°C (−10°F), at least 5-log E. coli O157:H7 inactivation was consistently demonstrated at −11°C (12°F), and at least 5-log L. monocytogenes inactivation was consistently demonstrated at 0°C (32°F).

Sign in / Sign up

Export Citation Format

Share Document