• 한국식품위생안전성학회지
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• 제27권1호
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• pp.81-86
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• 2012

본 연구는 황련, 감초, 오미자 그리고 산수유 한약재 복합추출물의 $E.$ $coli$ O157:H7에 대한 항균효과와, 한약재 복합추출물과 염소산나트륨 합제의 $E.$ $coli$ O157:H7 감염 마우스에 대한 항균효과를 평가하기 위해 수행되었다. 한약재 복합추출물, CGSC10을 이용하여 $E.$ $coli$ O157:H7에 대한 항균효과 확인 시험을 수행한 결과, CGSC10 5, 10, 그리고 20%를 첨가한 배지에서 30시간 동안 배양한 후, $E.$ $coli$ O157:H7의 성장이 각각 34.7, 60.2, 그리고 76.4% 억제되는 효과가 관찰되었다. 또한, $E.$ $coli$ O157:H7을 감염시킨 마우스에 CGSC10, 염소산나트륨, 그리고 CGSC10와 염소산나트륨 합제(CGSCS10)를 음용수를 통해 투여한 결과, 투여 3일째부터, 모든 투여군에서 대조군과 비교하여 $E.$ $coli$ O157:H7의 균수가 유의성 있게 감소하였으며($p$ < 0.001), 투여 7일째에는, 10% CGSC10, 15mM 염소산나트륨, 그리고 CGSCS10을 투여한 군에서 대조군과 비교하여 $E.$ $coli$ O157:H7의 균수가 각각 27.1, 67.7, 그리고 83.3% 정도 감소하는 결과를 나타내었다. 따라서 본 연구의 결과로부터, CGSCS10을 $E.$ $coli$ O157:H7에 감염된 마우스에 음수로 투여할 경우, 감염증상을 완화 시킬 수 있을 것으로 기대된다.

• 한국식품저장유통학회지
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• 제5권3호
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• pp.286-291
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• 1998

4종류의 식중독세균(Escherichia coli O157:H7, Listeria monocytogenes, Staphylococcus aureus 196E, Salmonella typhimurium)에 대하여 녹차 물추출물에 의한 항균작용을 조사하였다. 각 식중독세균을 tryptic soy broth(TSB)에 약 $10^{5}$CFU/ml 정도 되게 접종하여 35$^{\circ}C$에서 30시간 배양하였다. 세균의 배양중 대수증식기의 중기 혹은 말기에 녹차 물추출물을 0-2%(w/v)의 농도로 첨가하였을 때 증식억제 정도를 생균수 변화로서 비교하였다. 식중독세균의 증식은 첨가한 녹차 물추출물의 농도에 비례하여 억제되었으며 대수증식기 말기의 세균이 중기의 세균에 비하여 녹차 물추출물에 대한 내성이 컸다. Gram 양성균(L. monocytogenes, S. aureus)의 경우가 Gram 음성균(E. coli O157:H7, S. typhimurium)에 비하여 녹차 물추출물에 의한 억제효과는 월등히 컸다. 녹차 물추출물에 의한 증식억제 효과의 크기는 S. aureus, L. monocytogenes, E. coli O157:H7의 순이었으며 S. typhimurium에서 가장 강한 내성을 나타내었다.다.

• Journal of Microbiology and Biotechnology
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• 제27권1호
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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.

• Preventive Nutrition and Food Science
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• 제6권1호
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• pp.6-9
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• 2001

Minimal inhibitory concentrations (MIC) and antimicrobial effects of glycerol monolaurate (monolaurin) and organic acids, either alone or in combination, against Escherichia coli O157:H7 in tryptic soy broth were determined. MIC values of monolaurin(ML), acetic (AA), citric (CA), lactic (LA) and hydrochloric acid (HCl) were 300$\mu\textrm{g}$/mL (0.03%), 1250$\mu\textrm{g}$/mL(0.125%), 5000$\mu\textrm{g}$/mL(0.5%), 2500$\mu\textrm{g}$/mL(0.25%) and 2500$\mu\textrm{g}$/mL(0.25), respectively. When 150$\mu\textrm{g}$/mL of ML was combined with 50$\mu\textrm{g}$/mL AA, 250$\mu\textrm{g}$/mL HCl and 125$\mu\textrm{g}$/mL LA, the combined agents did not increase the inhibitory effect of the most active single compound alone. This result indicates that there was little interaction between ML and A, HCl and LA. However, the combination of 150$\mu\textrm{g}$/mL ML and 250$\mu\textrm{g}$/mL CA synergistically inhibited growth of E. coli O157:H7. The present study showed that the nature of combined antimicrobial response against E. coli O157:H7 was complex, but this information would be useful for determining interaction that could compromise effectiveness in food systems.

• 한국식품과학회지
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• 제53권6호
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• pp.819-822
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• 2021

To enhance phage endolysin-mediated cell wall disruption of Escherichia coli O157:H7, the cells were co-treated with aromatic compounds, namely thymol or eugenol, found in essential oils and endolysin LysECP26. Interestingly, the minimal inhibitory concentrations of LysECP26 was four times lower when used in combination with either of the two compounds than when it was used alone. This synergistic activity was also confirmed by viable cell counting. Within 1 h of LysECP26 and eugenol or thymol co-treatment to the cells, there was a 2.3 or 3.8 log CFU/mL reductions, respectively. Additionally, field emission scanning electron microscopy showed cell wall disruption and severe morphological alterations of the cells in case of the combination treatments. Therefore, endolysin and thymol or eugenol co-treatment can help in developing efficient bio-control strategies against gram-negative pathogen E. coli O157:H7.

• Asian-Australasian Journal of Animal Sciences
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• 제22권2호
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• pp.238-245
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• 2009

Pure culture experiments were conducted to assess the bacteriostatic and bactericidal effects of phlorotannins (PT) isolated from Ascophyllum nodosum (brown seaweed) on Escherichia coli O157:H7. In Exp. 1, one non-O157:H7 strain (25922) and three strains of E. coli O157:H7 (3081, EDL933 and E318N) were cultured in M9 medium with PT included at 0 (control), 25, 50 or $100{\mu}g/ml$ (n = 3). Bacterial growth was monitored by $OD_{600}$ at 0, 4, 6, 12 and 24 h, and by dilution plating at 0, 4, 6 and 24 h. All strains were inhibited (p<0.001) by PT to varying degrees. At 50 or $100{\mu}g/ml$, PT prevented growth of all four strains. At $25{\mu}g\;PT/ml$, growth of 25922, 3081, E318N and EDL933 was inhibited for 6, 12 and 24 h, respectively, but 25922 and 3081 resumed growth by 12 and 24 h. Direct plating confirmed bactericidal effects of PT on all four strains at $100{\mu}g/ml$, and on EDL933 and E318N at $50{\mu}g/ml$. In Exp. 2, strains 25922 and 3081 were incubated with no tannins or with $50{\mu}g/ml$ of PT, purified condensed tannins (CT) from Quebracho (Schinopsis balansaei), or purified tannic acid from Rhus semialata (Anacardiaceae) as hydrolysable tannins (HT). Strain 3081 was unaffected by HT or CT, but was completely inhibited (p<0.001) by PT at 4, 6 and 24 h. Strain 25922 was unaffected by HT, slightly inhibited by CT, and almost eradicated by PT at 4 and 6 h. Transmission electron microscopy revealed tannin-mediated alterations to bacterial cell walls. Phlorotannins from A. nodosum exhibit growth-inhibiting and bactericidal effects in vitro against the strains of E. coli O157:H7 investigated. Anti-E. coli efficacy of A. nodosum PT is superior to that of terrestrial tannins purified from Quebracho and from Rhus semialata.

• 한국식품과학회지
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• 제32권1호
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• pp.218-224
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• 2000

분자량이 상이한 세 종류의 키토산의 항균활성을 E. coli O157 : H7, S. aureus 및 C. albicans 균주를 이용하여 측정, 분석하였다. E. coli O157 : H7와 S. aureus에 대해서는 분자량 10,000인 키토산이 가장 강한 항균활성을 보였으며 C. albicans에 대해서는 6량체의 키토산 올리고당이 가장 강한 활성을 나타내었다. 키토산 첨가농도는 E. coil O157 : H7와 S. aureus의 경우 0.1 mg/mL의 농도에서, C. albicans의 경우는 chitohexaose 1 mg/mL의 농도에서 항균활성이 가장 높았다. 모든 키토산 처리구에서 미생물 사멸 속도는 키토산 처리 1시간 이내에서 가장 높게 나타났으며 그 이후로는 점차 낮은 속도를 보였다. 사멸되었거나 파손된 미생물 세포로부터 유래되는 단백질, 핵산물질 및 $Ca^{2+}$ 량은 키토산 처리 시간 이내에 가장 많았으며 ${\beta}-galactosidase$ 활성도 같은 시간대에서 가장 빠른 속도로 중대되는 것으로 나타났다. S. aureus에 대한 세포막 손상 정도를 측정하여 본 결과 전체 미생물균체중 약 10%에 상당하는 균수가 막손상을 가져 왔다. 따라서, 키토산은 고유의 양이온성 성질을 이용하여 미생물의 세포벽과 세포막에 결합하여 그 결과로 세포 내 물질의 세포 외로의 유출내지는 세포막 대사의 저해 등의 효과를 나타냄으로써 항균활성을 나타내는 것으로 추측되었다.

• 한국식품위생안전성학회지
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• 제13권1호
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• pp.1-5
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• 1998

본 연구는 E. coli O157:H7에 대한 LP system(lactoperoxidae/thiocyanate/hydrogen peroxide)의 항균효과를 측정하기 위해 수행되었다. 초기 접종수준($10^{2},\;10^{4},\;10^{7}cfu/ml$), LP의 농도 (10ppm, 20ppm, 30ppm), 배지종류 (TSB, UHT milk, raw milk), 배양온도 ($5^{\circ}C,\;10^{\circ}C,\;15^{\circ}C$) 등에 따라 E. coli O157:H7에 대한 항균효과를 측정, 비교한 결과, 초기 접종수준을 $10^2/ml$으로 하였을 때와 LP의 농도를 10ppm 및 $5^{\circ}C$ 배양에서 항균력이 가장 높게 나타났다.

• Journal of Microbiology
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• 제44권1호
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• pp.92-97
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• 2006

We developed an mPCR assay for the simultaneous detection, in one tube, of Escherichia coli O157:H7, Salmonella spp., Staphylococcus aureus and Listeria monocytogenes using species-specific primers. The mPCR employed the E. coli O157:H7 specific primer Stx2A, Salmonella spp. specific primer Its, S. aureus specific primer Cap8A-B and L. monocytogenes specific primer Hly. Amplification with these primers produced products of 553, 312, 405 and 210 bp, respectively. All PCR products were easily detected by agarose gel electrophoresis, and the sequences of the specific amplicons assessed. Potential pathogenic bacteria, in laboratory-prepared and four commercially available kimchi products, were using this mPCR assay, and the amplicons cloned and sequenced. The results correlated exactly with sequences derived for amplicons obtained during preliminry tests with known organisms. The sensitivity of the assay was determined for the purified pathogen DNAs from four strains. The mPCR detected pathogen DNA at concentrations ranging from approximately 0.45 to $0.05\;pM/{\mu}l$. Thus, this mPCR assay may allow for the rapid, reliable and cost-effective identification of four potentially pathogens present in the mixed bacterial communities of commercially available kimchi.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2003년도 생물공학의 동향(XII)
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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.