• Journal of Microbiology and Biotechnology
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• v.27 no.1
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• pp.67-71
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• 2017

This study examined the antimicrobial activity of flaxseed meal extract (FME) against Staphylococcus aureus and Escherichia coli O157:H7 inoculated on red mustard. With the treatment of 0.7% FME for 3 min, the reduction levels of S. aureus and E. coli O157:H7 populations were 1.23 and 1.83 log CFU/g, respectively. In addition, the combined treatment of 0.7% FME at $50^{\circ}C$ for 3 min reduced the populations of the pathogenic bacteria by 2.28 and 2.41 log CFU/g, respectively. The color and the vitamin C content were not significantly different between treatments. Thus, FME can be used as a novel antimicrobial agent in fresh-cut vegetables.

• Korean journal of food and cookery science
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• v.18 no.1
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• pp.57-62
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• 2002

The purpose of this study was to investigate the antibacterial activity of green tea in mayonnaise against pathogenic bacteria (Escherichia coli O157:H7 and Salmonella typhimurium). Mayonnaise was prepared with salad oil, egg yolk, sugar, salt and vinegar, and green tea powder was added to the mayonnaise at 0.1, 0.3 and 0.5% for the experiment. Then, the mayonnaise samples with various levels of green tea were inoculated with about 10$\^$6/ cells/g of E. coli and S. typhimurium per 1 gram of mayonnaise and stored at 5$^{\circ}C$, 15$^{\circ}C$ and 25$^{\circ}C$ for 3∼9 days. Antibacterial activity of green tea was tested by the colony counting method for E. coli on violet red bile agar(VRBA) and S. typhimurium on xylose lysine desoxycholate agar(XLDA). The D-values of E. coli controls were 2.89, 2.73 and 2.13 days while those of S. typhimurium controls were 0.58, 0.53 and 0.52 days at 5$^{\circ}C$, 15$^{\circ}C$ and 25$^{\circ}C$, respectively Inhibitory effect of green tea in mayonnaise on the survival of E. coli and S. typhimurium was increased with increasing concentration of green tea and/or increasing storage temperature. The most effective antibacterial activity of green tea was shown against E. coli in mayonnaise during storage at 25$^{\circ}C$.

• Korean Journal of Veterinary Research
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• v.50 no.2
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• pp.113-116
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• 2010

To determine the prevalence of Escherichia (E.) coli O157 : H7 from pigs after the Hazard Analysis and Critical Control Point (HACCP) system has been applied to Korean swine farm since 2006, 291 fecal samples were tested between May and December in 2008. Four E. coli O157:non-H7 (1.4%) were isolated from 4 different non-HACCP-accredited farms and they didn't have virulent genes which can cause illness for human. Also, Clostridium (C.) perfringens, Salmonella spp. and E. coli enterotoxins were tested using multiplex PCR. The positive rate for these pathogens of non-HACCP-accredited farms was higher than that of HACCP-accredited farms, and especially in case of C. perfringens, E. coli enterotoxins LT and STa, it was statistically significant (p < 0.05). Thus, the early implementation of the HACCP program is expected to greatly contribute to the safety of livestock products as well as food hygiene.

• Journal of Dairy Science and Biotechnology
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• v.39 no.2
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• pp.68-77
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• 2021

This study aimed to evaluate the effects of antibacterial activity of Tibetan mushroom exopolysaccharide against foodborne pathogenic bacteria Staphylococcus aureus 305, Listeria monocytogenes ATCC19114, Escherichia coli O157:H7 ATCC42894 and Escherichia coli O55. The yield of exopolysaccharide isolated from Tibetan mushroom culture was 620 mg/L. The antibacterial activity of exopolysaccharide against foodborne pathogenic bacteria exhibited 15 mm and 12 mm clear zone against S. aureus 305 and L. monocytogenes ATCC 19114, respectively. However, no clear zone was observed against E. coli O157:H7 ATCC 42894 and E. coli O55. In conclusion, exopolysaccharide isolated from Tibetan mushroom culture have the antibacterial activity only against Gram-positive foodborne pathogenic bacteria.

• Korean Journal of Food Science and Technology
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• v.41 no.2
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• pp.225-229
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• 2009

The efficacy of ozone water in reducing food-borne pathogenic bacteria on High Density Polyethylene (HDPE) and wooden chopping boards in food industry was investigated in this study. 1-5 log reductions of E. coli O157:H7, S. aureus, S. Typhimurium, and B. cereus were observed with increasing concentrations of ozone water. The immersion treatment evidenced superior capability to inactivate food-borne pathogens than washing treatment. The Gram-negative bacteria, such as E. coli O157:H7 and S. Typhimurium, evidenced lower resistance against ozone water than was seen with the gram-positive bacteria, which included S. aureus and B. cereus. The sterilizing effects of ozone water on HDPE chopping boards was superior to that on wooden boards. This result might be utilized to remove food-borne pathogens from food contact surfaces in the food industry.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.10
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• pp.1337-1342
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• 2008

This study was conducted to investigate effects of chemical sanitizers on inhibiting foodborne pathogens, such as Listeria monocytogenes (L. monocytogenes), Salmonella Typhimurium (S. Typhimurium), and E scherichia coli O157:H7 (E. coli O157:H7), on cabbages. Cabbages were inoculated with the culture cocktail of pathogens and treated with water, 100 ppm commercial chlorine, and 50, 100, and 200 ppm chlorine dioxide ($ClO_2$) for 1, 5, and 10 min at room temperature ($22{\pm}2^{\circ}C$). Treatments with water did not significantly reduce levels of three pathogens whereas other treatments with chemical sanitizers significantly reduced levels of three pathogens. Treatment with 200 ppm $ClO_2$ for 10 min was the most effective at inhibiting pathogens and reduction levels were 1.90, 1.92, and 1.98 log CFU/g for L. monocytogens, S. Typhimurium, and E. coli O157:H7, respectively. Levels of reduction were increased with the increase of $ClO_2$ concentrations. When chemically injured cells were investigated, there were no significant differences on the levels of injured cells between before and after treatment with commercial chlorine and $ClO_2$. These results suggest that $ClO_2$ can be used as an alternative sanitizer for reducing pathogens on fresh produces.

• Journal of Food Hygiene and Safety
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• v.22 no.1
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• pp.37-44
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• 2007

The approval of use of certain food-grade phosphates as food additives in a wide variety of meat products greatly stimulated research on the applications of phosphates in foods. Although phosphates have never been classified as antimicrobial agents, a number of investigators have reported that phosphates have antimicrobial activities. Phytic acid is a natural plant inositol hexaphosphate constituting 1-5% of most cereals, nuts, legumes, oil seeds, pollen, and spores. In this study, we investigated antibacterial activities of sodium phytate(SPT), sodium pyrophosphate (SPP), sodium tripolyphosphate (STPP) on Escherichia coli O157:H7 on tryptic soy broth and in beef, pork and chicken. In tryptic soy broth, SPT, SPP and STPP at the concentrations of 0.05, 0.1, and 0.5% effectively inhibited the growth of Escherichia coli O157:H7 in a concentration-dependent manner. The bactericidal activity of SPT was the stronger than that of SPP or STPP at the same concentrations. In addition, the antibacterial effects of SPT, SPP and STPP at the concentrations of 0.05, 0.1, 0.3, and 0.5% on Escherichia coli O157:H7 were also investigated in raw or cooked meats including beef, pork and chicken. SPT, SPP and STPP significantly inhibited the bacterial growth in a dose-dependant manner (p<0.05). The bactericidal effect of SPT was stronger than that of SPP or STPP. The addition of SPT, SPP and STPP in meats increased meat pHs. SPP and STPP also increased the levels of soluble orthophosphate in meats but STP did not. These results indicate that SPT is very effective for inhibition of bacterial growth and that can be used as a muscle food additive for increasing functions of meats.

• 한국생물공학회:학술대회논문집
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• 2003.04a
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• pp.635-638
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• 2003

For the acute assessment on biological toxicity of wastewater, surface plasmon resonance(SPR) based cell viability detection was performed using gold surface-confined cell as a result of adhesion-modifying chemicals. Escherichia coli O157:H7 (E. coli O157:H7) was investigated after exposure to EDTA. Cells were immobilized on gold coated slide glass for SPR analysis by the method of cross-linking carboxyl group on the bacterial surface with amine group of poly-L-lysine that had been coupled to the gold surface modified by a self-assembled monolayer of 11-mercaptounde canoic acid (11-(MUA)). Reflective intensity of each flow step was changed with respect to confect of ethylenediaminetetraacetic acid (EDTA) disodium salt and phosphate-buffered saline (PBS) solution. The proposed detection technique can be used for biological toxicity test.

• Journal of Food Hygiene and Safety
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• v.28 no.2
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• pp.174-180
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• 2013

This study investigated the microbiological contamination of tomato in cultivation and distribution stage. Growth of Escherichia coli O157:H7 and Listeria monocytogens examined in tomato extracts (0.1, 1.0, and 10.0%) and incubation temperatures (5, 15, 25, and $35^{\circ}C$). In cultivation stage of tomato, total aerobic bacteria were 7.77 log CFU/g in gloves of APC (Agricultural Products Processing Center) worker and Bacillus cereus were 0.33 log CFU/g at nutrient tank, respectively. And Staphylococcus aureus, Salmonella spp., were not detected. After APC stage, total aerobic bacteria were significantly higher compared with before-APC stage. Among of general, pesticide-free and organic produce in tomato were no significant difference in microbial contamination. Coliforms of tomato in small vinyl package were significantly higher when compared to tomato in whole boxes package. There was no significant difference in bacteria count between unwashed tomato and washed tomato using tap water for one minute. The growth of E. coli O157:H7 and L. monocytogens in tomato extracts were decreased significantly as the concentration increased, and the microbial population was reached the lowest point during storage in 10% tomato extracts concentration for 72h at $5^{\circ}C$. However, the population of E. coli O157:H7 and L. monocytogens were gradually increased at 7.33~8.51 and 7.73~8.60 log CFU/ml during storage at $15{\sim}35^{\circ}C$ for 72h, respectively.

• Korean Journal of Veterinary Research
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• v.42 no.2
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• pp.231-239
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• 2002

Proteomics is an emerging powerful tool in studying protein expression and function. At present study, proteomics was employed to evaluate the antigenicity among Escherichia coli O157:H7 strains using 2-dimensional gel electrophoresis (2-DE) and immunoblotting, SDS-PAGE and immunblotting analysis revealed no big differences among E coli O157:H7 strains. 2-DE analysis, however, revealed common antigens as well as specific antigens. The immunoblotting analysis revealed 20 common antigenic spots among E coli O157:H7 strains. In addition, there were 3 and 13 spots as common antigens between ATCC 43894 and KSC 109, and between ATCC 43894 and ACH 5, respectively. Antigenic spots specific for individual strain were also identified as 15, 8 and 22 for ATCC 43894, ACH 5 and KSC 109, respectively. The common antigens would be useful by employing either vaccine development or diagnosis marker, or both, whereas the specific antigens of individual strains would be applicable for epidemiological study. This study suggest that proteome analysis, representative as 2-DE, is valuable tool in exploring the E. coli antigenicity.