• 대한수의학회지
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• 제33권3호
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• pp.419-427
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• 1993

Thirteen strains of Clostridium perfringens were isolated from the pigs with hemorrhagic enteritis. The characteristics of the outbreaks, clinical signs and lesions were examined. The biochemical properties, type of toxin and susceptibility to antimicrobial agents of the isolates were investigated. The results could be summarized as follows ; 1. Almost of the pigs affected with hemorrhagic enteritis, 17 cases examined from 1989 to 1992, were piglets less than 7 day old. 2. The average mortality rate of piglet less than 7 day old affected with hemorragic and necrotic enteritis was 48.5%. 3. The clinical signs of pigs with hemorrhagic enteritis were depression, hemorrhagic diarrhea, anemia and dehydration. Necropsy of the infected pigs showed typical hemorrhage of upper intestine and necrosis of mucosal membrane. 4. The characteristic biochemical properties of the isolates were 2-band hemolysis, positive reaction of reverse CAMP test and formation of LV precipitate in egg yolk medium. 5. The toxin type of the 13 isolates, investigated by mouse inoculation test, was all type C strains of Clostridium perfringens. 6. In susceptibility test to antimicrobial agents, 13 isolates of Clostridium perfringens were highly sensitive to ampicillin, enrofloxacin(Baytril), cephalothin, penicillin and trimethoprim-sulfamethoxazole.

• Bulletin of the Korean Chemical Society
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• 제32권8호
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• pp.2577-2583
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• 2011

We have designed a 20-residue hybrid peptide CA(1-8)-MA(1-12) (CAMA) incorporating residues 1-8 of cecropin A (CA) and residues 1-12 of magainin 2 (MA) with high bacterial cell selectivity. CAMA-P2 is an ${\alpha}$-helical antimicrobial peptide designed from a CAMA hybrid peptide and substitution of Gly-Ile-Gly hinge sequence of CAMA to Pro influences the flexibility at central part of CAMA. Based on structure-activity relationships of CAMA peptides, to investigate the effects of the total positive charges on antimicrobial activity of CAMA-P2, the $Ser^{14}{\rightarrow}$Lys analogue (CAMA-syn1) was synthesized. The role of tryptophan at C-terminal ${\alpha}$-helix on its antimicrobial activity as well as synergistic activity was also investigated using $Ser^{14}{\rightarrow}$Lys/$Phe^{18}{\rightarrow}$Trp analogue (CAMA-syn2). Also, we designed CAMA-syn3 by substitution of $Lys^{16}$ located opposite side of substituted $Lys^{14}$ of CAMA-syn1 with Leu residue, resulting in increase of hydrophobicity and amphipathicity of the peptide. All of CAMA-syn analogues showed good antimicrobial activities similar to those of CAMA and CAMA-P2. The CAMA-syn1 and CAMA-syn2 showed low hemolytic activity and cytotoxicity against human keratinocyte Haca-T cells while CAMA-syn3 showed hemolytic activity and cytotoxicity at its MIC value. We then investigated their abilities to act synergistically in combination with the antimicrobial flavonoids and synthetic compounds screened in our laboratory. The results showed that all peptides exhibited synergistic effects with dihydrobinetin, while only CAMA-syn2 exhibited synergistic effects with YKAs3001 against both S. aureus and MRSA, suggesting that Trp residue at C-terminus of CAMA-syn2 may facilitate the polar antibiotic flavonoids and synthetic compounds to permeabilize the membrane. This study will be useful for the development of new antibiotic peptides with potent antimicrobial and synergistic activity but without cytotoxicity.

• Journal of Microbiology and Biotechnology
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• 제32권8호
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• pp.1003-1010
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• 2022

The purpose of this study was to examine the phytochemical compounds and antibacterial activity of Coffea robusta leaf extract (RLE). The results indicated that chlorogenic acid (CGA) is a major component of RLE. The minimum inhibitory concentrations (MICs) of RLE against Staphylococcus aureus, Bacillus subtilis, Escherichia coli, and Salmonella Typhimurium were 6.25, 12.5, 12.5, and 12.5 mg/ml, respectively. RLE effectively damages the bacterial cell membrane integrity, as indicated by the high amounts of proteins and nucleic acids released from the bacteria, and disrupts bacterial cell membrane potential and permeability, as revealed via fluorescence analysis. Cytotoxicity testing showed that RLE is slightly toxic toward HepG2 cells at high concentration but exhibited no toxicity toward Caco2 cells. The results from the present study suggest that RLE has excellent potential applicability as an antimicrobial in the food industry.

• 한국식품위생안전성학회지
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• 제10권1호
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• pp.33-39
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• 1995

The antibacterial and antifungal effect of grapefruit seed extract(GFSE) was investigated for its purpose of application to a diverse spectrum of field as sanitizers, disinfectants and preservatives. GFSE showed coparatively high content of such flavoniods as naringin and hesperidin and ascorbic acid. GFSE containing a low level of organic acids is a heavy viscous and water-soluble liquid. As a result of the antimicrobial test of GFSE, Bacillus subtilis and Aspergillus oryzae did not survive at detectable levels when treated with more than 100 ppm of GFSE. The minimum inhibitory concentrations of GFSE for a wide variety of pathogenic and putrefactive bacteria, fungi and yeasts were 100 ppm and 250 ppm, respectively. In the comparable electron micrograph of microbial cells treated with GFSE or not, we could conclude that GFSE destroy microorganisms by disrupting the functions of the cell wall membrane and microbial spores.

• 한국식품영양과학회지
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• 제27권6호
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• pp.1086-1093
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• 1998

The antimicrobial effect of mixed solutions of grapefruit seed extract(250ppm) and ascorbic acid(1%) on the spoilage microorganisms such as Staphylococcus epidermis, Escherichia coli, Pseudomonas syringae, Candida albicans and Corynebacterium xerosis isolated from the spoiled soybean sprouts were investigated. Cell wall and membrane were partially destroyed and the contents of the destroyed cell were exuded after treatment. Packages with 30 m cast polypropylene(CPP), 16 m polyolefin(RD 106) and 10 m high density polyethylene(HDPE) were applied for soybean sprouts dipped in mixed solutions respectively. Oxygen and carbon dioxide concentration inside packages were dependent on the kind of films during storage at 5oC. The antimicrobial activity of mixed solutions was maintained for 5 days at CPP package. Package with HDPE showed a severe browning than the others after 5 days. Ascorbic acid content of mixed solution treatment was higher than that of control for each package.

• 한국식품영양학회지
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• 제13권2호
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• pp.139-145
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• 2000

To separate anticaries and antiinflammation from Aloe vera peel, we investigated a inhibited effect of Streptococcus mutans JC-2 that was antibiosis, glucosyltransferase activity about aloe-emodin and barbaloin. Aloe-emodin and barbaloin had strong antibiosis activity against Streptococcus mutans JC-2, they were especially antibiosis effect to low growth and prolong lag phase at attachment concentration 100$\mu\textrm{g}$/mL. The reduction rate of a culture fluid became to lessen than the comparison group for aloe-emodin and barbaloin. The intracellular materials of Streptococcus mutans JC-2 were to leakage as much as attachment concentration addition of aloe-emodin and barbaloin but there was no significant difference membrane demage between two active substances. The activity of GTase was inhibited by aloe-emodin and barbaloin and their inhibition rate was respectively 99.8%, 98.4% at the attachment concentration 100$\mu\textrm{g}$/mL.

• 한국어업기술학회:학술대회논문집
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• 한국어업기술학회 2001년도 추계 수산관련학회 공동학술대회발표요지집
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• pp.147-148
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• 2001

Many people living in Asia countries, particularly Korea, Japan and China, have consumed very widely fresh seafood products, such as shrimps, oysters, mussels and other marine invertebrates and fishes, without any heating or cooking. A variety of Vibrio spp., including V. parahaemolyticus, V. cholera. V. vulnificus, and V. fluvialis, lives in these seafoods and cause great problems associated with human disease. A strong antimicrobial agent to effectively inhibit the growth of these pathogenic bacteria in in vivo or in vitro is urgently need for preventing fish and human diseases. (omitted)

• 한국어업기술학회:학술대회논문집
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• 한국어업기술학회 2001년도 추계 수산관련학회 공동학술대회발표요지집
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• pp.151-152
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• 2001

Chitin, a polymer of N-acetylglucosamine ($\beta$-1,4 linked 2-acetamido-D-glucose), is a cellulose-like biopolymer present richly in the exoskeleton of crustaceans and in cell walls of fungi, insects and yeast. Chitosan is derived from chitin by deacetylation, to different degrees, in the presence of alkali. [l]. Recent studies for chitin and chitosan have been concentrated in bioactivities such as antitumor activity, immuno-enhancing effects, enhancing protective effects against infection with some pathogens in mice, and antimicrobial activeity [2]. (omitted)

• 대한환경공학회지
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• 제27권7호
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• pp.771-776
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• 2005

최근 항균 성능이 뛰어나면서도 인체에 유해하지 않은 나노 사이즈 은 입자를 이용한 항균 제품 개발 및 연구가 활발히 이루어지고 있음에 따라, 나노 사이즈의 은 입자를 보다 쉬운 방법으로 균일하게 제조하고, 그 특성을 평가하는데 많은 관심이 집중되고 있다. 본 연구에서는 은 이온의 광환원을 통해 나노 은 입자를 $15{\sim}20\;nm$ 크기로 균일하게 제조한 뒤, 나노 은 입자의 농도, pH, 온도가 변화함에 따른 항균 특성을 살펴보고 이를 정량적으로 평가, 은 이온의 항균 특성과 비교하였다. 또한 주사 전자 현미경과 투과 전자 현미경을 통하여 나노 은 입자의 미생물 불활성화 특성을 은 이온의 미생물 불활성화 특성과 비교하였다. 주요 결과로는 나노 은 입자의 항균 효과는 동일한 은 농도를 기준으로 하였을 때 은 이온의 항균 효과에 비하여 약 20배 정도 적은 것을 알 수 있었다. 또한 나노 은 입자의 농도, 온도가 높을수록 항균 성능은 향상됨을 알 수 있었으며 이는 은 이온의 실험 결과와 일치한다. 그러나 나노 은 입자의 항균 성능은 높은 pH에서 향상된 반면, 은 이온의 경우 pH 변화에 따른 항균 성능 변화가 관찰되지 않았다. 나노 은 입자와 은 이온에 의해 불활성화된 미생물을 주사 전자 현미경과 투과 전자 현미경으로 관찰한 결과, 나노 은 입자는 미생물 세포막을 크게 손상시키는 반면, 은 이온은 그렇지 않았다. 은 이온의 경우 은 이온이 미생물 안으로 흡수되어 세포질막을 손상시켜 미생물을 불활성화 시키는 것으로 알 수 있었다.

• 한국식품저장유통학회지
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• 제11권3호
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• pp.411-416
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• 2004

식물성 천연항균제인 자몽종자추출제재(Boatanical antimicrohiagent-grapefruit seed extract mixture : BAAG)의 항균특성을 구명하고, 과채류의 선도유지제로서의 기능과 효능을 입증하기 위하여 BAAG를 조제하여 과채류의 저장, 유통중 발생하는 변패균주, Fuarium solani, Botrytis cinerea Pencilliumcrutosua Ewinia carotovora Phoma destructiva and Alternaria radirina등을 공시균주로 사용하여 Paper disk method에 의한 농도별 항균력을 실험한 결과,변패미생물에 대하여 농도에 비례하여 상당한 항균효과를 보였으며, 또한 생육저해곡선에서는 500 $\mu$g/mL 이상에서 미생물의 생육이 완전히 억제되는 것을 볼수 있었다. 그리고 열 및 pH 안전성에 대해서도 열처리의 온도와 pH 범위에 관계없이 항균력을 보임으로써 열과 pH에 안정한 것으로 나타났다. 또한 항균력에 의한 미생물의 생태변화에 대한 전자현미경적 검사(SEM에서도 항균물질이 미생물 세포벽 또는 세포막의 기능성을 파손하여 삼투기능이 상실됨으로 해서 미생물의 생리가 중단되고 생육이 억제되는 것을 볼 수 있으며, 균체내부에 빈 사멸 균체들이 증대함을 알 수 있었다. 이상의결과로 미루어, BAAG는 항균포장원지 또는 항균포장상자의기능성 소재로 이용될 수 있음을 확인할 수 있었다.