• Korean Journal of Veterinary Research
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• v.33 no.3
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• pp.443-454
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• 1993

Shiga-like toxin-II(SLT-II)-producing Escherichia coli 0157 : H7 strain B2387이 분비하는 SLT-II가 gnotobiotic자돈에서의 뇌혈관 병변을 일으키는 pathogenesis에 관해서 실험을 했다. 제왕절개 수술로 태어난 자돈들을 두 그룹으로 나누어서, 한 그룹에는 SLT-II 중화항체를 포함한 혈청을 구강을 통해서 수동면역을 시키고, 또다른 한 그룹에는 SLT-II 중화항체가 포함되어 있지 않은 혈청을 구강을 통해서 수동면역시켰다. 24시간후 두 그룹 모두에게 SLT-II producing Escherichia coli O157 : H7 strain B2387를 구강으로 접종했다. SLT-II 중화항체가 포함되어 있지 않은 혈청으로 수동면역시킨 그룹의 자돈들은 설사와 맹결장염, 신경증상, 뇌혈관병변을 일으키고, plasma의 prostacyclin의 level이 증가했다. 하지만 SLT-II 중화항체가 포함되어 있는 혈청으로 수동면역시킨 그룹의 자돈들은 설사와 맹결장염은 유발했지만, 신경증상과 뇌혈관병변은 관찰되지 않았고, prostacyclin의 level도 증가하지 않았다. 이런 실험결과는 SLT-II 중화항체는 뇌혈관병변은 방어하지만 맹결장염은 방어하지 못한다는 의미를 나타내며, prostacylin의 증가는 뇌혈관의 endothelium의 병변을 의미한다.

• Proceedings of the Korean Society of Food Hygiene and Safety Conference
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• 2002.05a
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• pp.158-159
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• 2002

• Journal of Food Hygiene and Safety
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• v.13 no.1
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• pp.1-5
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• 1998

This study was carried out to measure the antibacterial effect of lactoperoxidase/ thiocyanate/hydrogen peroxide system (LP system) against E. coli 0157:H7. When the initial inoculum levels (($10^{2},\;10^{4},\;10^{7}cfu/ml$), concentration of LP (10 ppm, 20 ppm, 30 ppm), culture media (TSB-YE, UHT milk, raw milk) and storage temperatures ($5^{\circ}C,\;10^{\circ}C,$15$^{\circ}C$) were set up differently for the experiment and the antibacterial effect was compared, the highest antibacterial effect of LP system was shown at $10^{2}cfu/ml$ of initial inoculum level, 10 ppm of LP concentration and $5^{\circ}C$ of incubation temperature.

• Preventive Nutrition and Food Science
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• v.5 no.3
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• pp.131-135
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• 2000

The inhibitory effect of various organic acids on the growth and survival of Escherichia coli O157:H7 in tryptic soy broth with 0.6% yeast extract at 37$^{\circ}C$ or 4$^{\circ}C$ was determined. Minimal inhibitory pHs of acetic acid, citric acid, fumaric acid, hydrochloric acid and lactic acid were 5.0, 4.0, 4.5, 4.0 and 4.5, respectively. Acetic acid (0.012 m) showed the strongest antimicrobial activity, based on the pH values or equivalent molar concentrations, followed by lactic acid (0.0006 M), fumaric acid (0.004M) and citirc acid (0.004 M), respectively, E. coli O157:H7 with an initial inoculum of {TEX}$10^{7}${/TEX} CFU/ml and {TEX}$10^{5}{/TEX} CFU/ml in tryptic soy broth supplemented with 0.6% yeast extract, acidified to target pH with citric, fumaric and lactic acids at 37$^{\circ}C$, was completely inactivated after 7 d and 5 d incubation, respectively, except for the acetic acid (9 d). The bactericidal effect decreased at the same pH when the incubation temperature a was reduced from 37$^{\circ}C$ to 4$^{\circ}C$. The pH values of 0.2% acetic (pH 5.1), 0.6% citric (pH 4.2) and 0.4% lactic acid (pH 4.3) in TSBYE were almost correspondent to the minimal inhibitory pH values on E. coli O157:H7 of acetic (pH 4.0), citric (pH 4.0) and lactic acids (pH 4.5).

• Food Engineering Progress
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• v.13 no.1
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• pp.64-69
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• 2009

From the 25 fresh fruits and vegetable products, 1,250 isolates grown on MRS agar media were screened for the inhibitory activity on the growth of Escherichia coli 0157:H7, Listeria monocytogenes, and Bacillus cereus as well as Lactobacillus plantarum, L. casei, and Lactococcus lactis subsp. lactis. Among them, 607 isolates (49% of total isolates) from 23 different foods produced growth inhibitory activity on the E. coli 0157:H7, L. monocytogenes, or B. cereus. When these isolates were screened for the inhibitory activity on the growth of L. plantarum, L. casei, and Lactococcus lactis subsp., 24 isolates (3% of total isolates) from 7 food samples showed bacteriocin-like activity. These isolates had typical physiological characteristics of lactic acid bacteria, which indicated these isolates were strains of lactic acid bacteria. The inhibitor from 3 out of 24 revealed as nicin. From the RAPD-PCR profiles, 24 strains was classified and it was also indicated that most of the strains isolated from same produce showed similar phylogenetic profile.

• Food Science and Biotechnology
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• v.17 no.6
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• pp.1203-1206
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• 2008

Silk fibroin (SF) film containing catechin was prepared and the antimicrobial activity as well as physical property of the film was examined. Tensile strength of the SF film decreased with increasing concentration of catechin, and water vapor permeability of the film decreased. The film's antimicrobial activity against Escherichia coli O157:H7 increased with increasing catechin concentration. Sausage samples were inoculated with E. coli 0157:H7 and Listeria monocytogenes, and the sausage packaged with the SF film containing catechin had a decrease in the populations of E. coli O157:H7 and L. monocytogenes by 0.83 and 0.85 log CFU/g after 12 days of storage, respectively, compared to the control. In addition, the sausage had a better quality than the control regarding lipid oxidation. Our results indicate that sausages can be packed with the SF film containing catechin to extend shelf life.

• Korean Journal of Food Science and Technology
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• v.32 no.1
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• pp.218-224
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• 2000

The antimicrobial activities of chitosan oligosaccharide(chitohexaose) and two types of chitosans M.W.(10,000 and M.W. 100,000) were examined against Escherichia coli O157 : H7(ATCC 43894), Staphylococcus aureus(ATCC 144458) and Candida albicans(KFRI 432). Chitosan with molecular weight of 10,000 showed the strongest antimicrobial activities to E. coil O157 : H7 and S. aureus, whereas chitohexaose acted most strongly against C. albicans. The most effective concentration of chitosan was measured to be 0.1 mg/mL for E. coil O157 : H7 and S. aureus, and that of chitohexaose to be 1 mg/mL for C. albicans. Antimicrobial activities of chitosans and chitohexaose were maintained for 60 min after their treatment. They were found to induce leakage of intracellular proteins and nucleic acids from treated microorganisms. The efflux determined by assaying the ${\beta}-galactosidase$ leaked from the lactose-induced E. coli O157 : H7 cells was observed to reach the highest level within 60 min after treatment with the antimicrobial agents and chitosan with 10,000 molecular weight gave the highest ${\beta}-galactosidase$ activity. Therefore, it is supposed that the antimicrobial activity of chitosan with its unique polycationic nature might be caused by its binding to anionic component(s) of the cell envelope and thereby inhibiting the membrane metabolism and/or leaking intracellular materials.

• Korean Journal of Veterinary Research
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• v.46 no.2
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• pp.135-142
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• 2006

Shiga toxin (stx) producing Escherichia coli (STEC) causes various clinical signs in animal and human. In this study, 255 fecal samples from calves showing diarrhea were collected from cattle farms in Chonnam province during the period from January 2005 to July 2005. Twenty six STEC (10%) were isolated from 255 fecal samples by PCR. The isolates displayed three different stx combinations (stx1 [69%], stx1 and stx2 [15%], and stx2 [38%]). The isolates were further studied for virulence associated genes and antimicrobial resistance to define the virulence properties. Intimin (eaeA), enterohemolysin (hlyA), and lipopolysaccharide (rfbE) virulence genes were detected in 6 (23%), 7 (26%), and 1 (3.8%) of the isolates, respectively, by PCR. One isolate possessing rfbE gene was typed as E. coli 0157 : H7 by agglutination test with O and H antisera. All 26 isolates showed susceptibility to amikacin (100%) and the majority of isolates showed high susceptibility to gentamicin (88.5%) and chloramphenicol (73.1%). But all isolates were resistant to penicillin. These results may provide the basic knowledge to establish strategies for the treatment and prevention of enteric disease in calves.

• Proceedings of the Korean Society for Food Science of Animal Resources Conference
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• 2003.06a
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• pp.15-23
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• 2003

식품으로 인한 질병은 개인의 생명을 위협할 뿐 아니라 건전한 노동력의 상실로 생산성을 감소시키고 의료비를 증가시켜 개인의 행복 및 국가 경제에 부담을 준다 (Buzby et al. 1996, Mead et at. 2000). HACCP와 여러 식품안전에 관한 규제의 시행 등의 많은 노력에도 불구하고 Salmonella serotypes, Staphylococcus aureus, Camplobacter jejuni, Campylobacter coli, enterotoxigenic and enteroinvasive Escherichia coli, Clostridium perfringens, Bacillus cereus와 같은 식품기원 병원성 세균으로 인한 질병은 줄어들고 있지 않다. 오히려 외식 위주로 변해가는 생활습관은 식품을 통한 이들 병원성 세균의 전파가능성을 증가시키고 있다. 게다가 새로운 병원성균 (Yersinia enterocolitica, Listeria monocytogenes, E. coli 0157:H7, Aeromonas spp., Plesiomonas spp.) 의 출현 또는 특정 식품과 연관되어 나타나는 특정 subtype (Salmonella serotype Enteritidis) 의 출현은 이제까지 통용되어왔던 식품기원 세균을 위한 제어프로그램과는 다른 각도로 재원을 활용해야 할 동기를 부여하고 있다.

• Korean Journal of Veterinary Service
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• v.25 no.1
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• pp.9-14
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• 2002

This survey was conducted to evaluate the microbiological quality and to detect of pathogenic microorganisms on the surface of slaughtered beef and pork products in two abattoirs located in Seoul from January 2001 through December 2001. Two hundred and twenty-five beef and 215 hog were surveyed for microbiological quality and 630 beef and 625 hog were detected for pathogenic microorgainsms. 1. The prevalence level on number of standard plate count(SPC) less than $10^4$cfu/$cm^2$in beef and hog were 89.8% and 90.7%, respectively. 2. Escherichia coli less than $10^2$cfu/$cm^2$ in beef and less than $10^3$cfu/$cm^2$ in hog were 98.2% and 99% 3. E coli 0157:H7 was recovered from 2 beef carcasses(0.32%), and Staphylococcus aureus from 12 pork carcasses(1.90%), Listeria monocytogenes from 1 beef and 4 pork carcasses (0.15%, 0.64%) and clostridium perfringens from 14 beef and 11 pork carcasses(2.22%, 1.76%), respectively.