• 생명과학회지
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• 제15권4호
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• pp.566-571
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• 2005

담수 식물 수초의 근계에 부착하는 미생물 중 중금속에 높은 저항성을 가지는 균을 분리하고 이들 중 Enterobacter cloaceae K41를 대상으로 생육최적조건을 검토한 결과는 LB배지에 $1\%$ yeast extract, $1\%$ lactose, $1\%$ NaCl, pH7.0, 최적 온도는 $37^{\circ}C$, 24시간 진탕배양 이었으며 중금속 첨가 시에는 침전을 막기 위하여 Nutrient 배지로 대체하였다. 이 분리균주와 표준균주인 Enterobacter cloaceae KCTC2519를 대상으로 중금속인 구리와 카드뮴이온에 대한 최소생육저지농도(MIC)를 비교한 결과 분리균주인 E. cloacear K41은 구리는 150 ppm, 카드뮴은 50 ppm농도까지 생육이 확인되었으나 표준균주는 구리 50ppm에서 생육이 확인되었으나 카르뮴이나 두 혼합 중금속에서는 확인되지 않는 차이를 나타내었다. 두 균주를 대상으로 유전적 성상을 비교한 결과 분리균주에선 plasmid가 검출되었으나 표준균주에는 없었다. 그리고 분리균주에서 6.4Kb 절편의 plasmid를 분리하여 구리, 카드뮴의 중금속에 민감한 균주인 E, coli $DH5{\alpha}$에 형질전환 시켜 생육에 영향을 미치는 정도를 비교하였다. 그 결과 형질전환 균주의 두 중금속에 대 한 최소생육저지농도가 구리는 7배, 카드뮴은 6배로 증가한 것을 알 수 있었다. 또한 중금속 흡착률은 형질전환 균주가 E. ccli $DH5{\alpha}$보다 구리가 1.3배, 카드뮴은 1.5배 증가함을 알 수 있었다. 따라서 이 plasmid가 중금속 저항성을 증가시키는데 관여하는 것으로 보였다.

• 한국식품과학회지
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• 제32권6호
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• pp.1396-1402
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• 2000

황련 추출물의 충치 예방효과 가능성을 확인하고자 S. mutans JC-2에 대하여 황련 추출물 및 그의 주요 활성성분의 항균효과, 산생성 억제효과, GTase 활성 억제효과, 균체부착 억제효과를 조사하였다. 메탄올 추출물은 물추물에 비하여 S. mutans에 대해 강한 항균효과를 나타내었으며, 이들 추출물의 S. mutans에 대한 최소저지농도(MIC)는 각각 $130\;{\mu}g/mL$, $200\;{\mu}g/mL$이었다. 황련의 주요 활성성분인 berberine과 palmatine의 MIC는 각각 $50\;{\mu}g/mL$, $110\;{\mu}g/mL$로 황련 추출물에 비하여 강한 항균활성을 나타내었다. 메탄올 추출물, berberine, palmatine을 $121^{\circ}C$, 15분간 열처리했을 때 항균효과가 전혀 감소하지 않아, 열에 매우 안정함이 확인되었다. S. mutans의 산생성에 대해서도 MIC 농도에서 메탄올 추출물, berberine, palmatine 모두 배양 24시간째에 산생성을 완전하게 억제하였다. GTase 활성 억제효과는 $300\;{\mu}g/mL$ 농도에서 메탄올 추출물, berberine, palmatine이 각각 23.2, 46.1, 17.1%의 억제율을 보였고, 물 추출물은 억제효과가 없었다. 반면에 S. mutans의 부착에 대해서는 생장 부분저해농도에서 물 추출물과 메탄올 추출물, beberine, palmatine의 경우 저해율이 각각 59.2%, 13.3%. 4.2%, 41.7%로써 물 추출물과 palmatine이 높은 저해율을 나타내었다. 이상의 결과로부터 황련 추출물의 충치억제효과는 주요 활성성분인 berberine과 palmatine의 S. mutans에 대한 항균효과, GTase 활성억제와 균체 부착 억제효과 등에 기인한 것이라 여겨지며, 황련 추출물이 충치예방을 위한 기능성 천연소재로서 매우 우수한 것으로 판단되었다.

• Journal of Microbiology and Biotechnology
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• 제19권4호
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• pp.391-396
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• 2009

The chemical compositions, and antibacterial and antifungal effects of essential oils extracted from three coniferous species, Pinus densiflora, Cryptomeria japonica, and Chamaecyparis obtusa, were investigated. Gas chromatography mass analysis of the essential oils revealed that the major components and the percentage of each essential oil were 16.66% $\beta$-phellandrene and 14.85% $\alpha$-pinene in P. densiflora; 31.45% kaur-16-ene and 11.06% sabinene in C. japonica; and 18.75% bicyclo [2,2,1] heptan-2-ol and 17.41% 2-carene in Ch. obtusa. The antimicrobial assay by agar disc diffusion method showed that $2.2{\mu}g$ of Ch. obtusa oil inhibited most effectively the growth of Escherichia coli ATCC 33312 and Klebsiella oxytoca ATCC 10031, whereas the C. japonica oil gave weak antimicrobial activity. The minimal inhibitory concentration(MIC) values for bacterial strains were in the range of 5.45-21.8 mg/ml depending on essential oils, but most Gram-negative bacteria were resistant even at 21.8 mg oil/ml. P. densiflora oil showed the most effective antifungal activity and the MIC values for Cryptococcus neoformans B42419 and Candida glabrata YFCC 062CCM 11658 were as low as 0.545 and 2.18 mg/ml, respectively. Cryp. neoformans B42419 was the most sensitive to all essential oils in the range of 0.545-2.18 mg/ml. Our data clearly showed that the essential oils from the three conifers had effective antimicrobial activity, especially against fungi.

• Journal of Periodontal and Implant Science
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• 제26권3호
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• pp.625-639
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• 1996

The purpose of this study was to an in estimate the antibiotic susceptibility of P. gingivalis and P. interrnedia isolate from the subgingival plaque to adult periodontitis. Six P. gingivalis and five P. intermedia bacterial strains were tested for their susceptibility to 10 antimicrobial agents under disc diffusion method and broth dilution method. Ten patients with deep pocket(6mm) were selected for this study. They had not taken antibiotics for 6 months and no history of dental treatment for 6 months before this study. The result were as follow : 1. For antibiotic disc diffusion method, six P. gingivalis and five P. interrnedia were tested with 10 antimicrobial agents which comprised penicillin, gentamycin, clindamycin, lincomycin, ampicillin, erythromycin, tetracycline, amikacin, chloramphenicol, vancomycin. The sensitive antibiotics were tetracycline, penicillin, ampicillin, vancomycin, chloramphenicol and resisitent antibiotics were lincomycin. The other antimicrobial agents were less active. 2. From the study of determination on the minimal inhibitory concentration(MIC) by broth dilution method, the MIC of tetracycline to P. gingivalis and P. intermedia were $0.5-1.0{\mu}g/ml$, $0.5{\mu}g/ml$, that of ampicillin were $1-8{\mu}g/ml$, that of clindamycin were $1-32{\mu]g/ml$, $8-16{\mu}g/ml$, that of lincomycin were $16-32{\mu}g/ml$, $2-32{\mu}g/ml$. These data suggest that tetracycline and ampicillin may be valuable drug in the elemination of P. gingivalis and P. interrnedia from the patients with adult periodontitis.

• 대한약침학회지
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• 제10권3호
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• pp.71-76
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• 2007

Objectives This experimental study was performed to investigate the continuous anti-bacterial potency of Coptidis rhizoma extract on cultivation of Staphylococcus species(S. aureus, S. epidermidis) that induce eye disease. Methods Minimal inhibitory concentration(MIC) was measured by dropping to $50{\mu}l$ diluted Coptidis rhizoma extract(100%, 10%, 1%, 0.1%) on S. aureus, S. epidermidis that were cultivated from 2 to 6 days. Anti-bacterial potency was measured by the size of inhibition zone with change of volume($20{\mu}l,\;30{\mu}l,\;40{\mu}l,\;50{\mu}l$). Results 1. Anti-bacterial potency of Coptidis rhizoma extract on S. aureus was appeared in 100%, 10% and was the same as anti-bacterial potency of 2 days and 6 days. Anti-bacterial potency with change of volume(100%) was increased in propotion to increase volume on all samples. Anti-bacterial potency with change of volume(10%) was increased in propotion to increase volume on all samples except $20{\mu}l$. Anti-bacterial potency of Coptidis rhizoma extract on S. aureus was appeared continuous. 2. Anti-bacterial potency of Coptidis rhizoma extract on S. epidermidis was appeared in 100%, 10% and was the same as anti-bacterial potency of 2 days and 6 days. Anti-bacterial potency with change of volume(100%) was increased in propotion to increase volume on all samples. Anti-bacterial potency with change of volume(10%) was appeared in $50{\mu}l$. Anti-bacterial potency of Coptidis rhizoma extract on S. epidermidis was appeared continuous. Conclusions Anti-bacterial potency of Coptidis rhizoma extract on cultivation of S. aureus & S. epidermidis was showed continuous.

• 한국생물정보학회:학술대회논문집
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• 한국생물정보시스템생물학회 2005년도 BIOINFO 2005
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• pp.139-143
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• 2005

Cytochrome P450 14${\alpha}$-sterol demethylase enzyme (CYP51) is the target a of azole type antifungals. The azole blocks the ergosterol synthesis and thereby inhibits fungal growth. A three-dimensional (3D) homology model of CYP51 from Candida albicans was constructed based on the X-ray crystal structure of CYP51 from Mycobacterium tuberculosis. Using this model, the binding modes for the substrate (24-methylene-24, 25-dihydrolanosterol) and the known inhibitors (fluconazole, voriconazole, oxiconazole, miconazole) were predicted from docking. Virtual screening was performed employing Structure Based Focusing (SBF). In this procedure, the pharmacophore models for database search were generated from the protein-ligands interactions each other. The initial structure-based virtual screening selected 15 compounds from a commercial available 3D database of approximately 50,000 molecule library, Being evaluated by a cell-based assay, 5 compounds were further identified as the potent inhibitors of Candida albicans CYP51 (CACYP51) with low minimal inhibitory concentration (MIC) range. BMD-09-01${\sim}$BMD-09-04 MIC range was 0.5 ${\mu}$g/ml and BMD-09-05 was 1 ${\mu}$g/ml. These new inhibitors provide a basis for some non-azole antifungal rational design of new, and more efficacious antifungal agents.

• Journal of Microbiology and Biotechnology
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• 제30권7호
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• pp.982-995
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• 2020

A putative multidrug efflux gene, yddA, was cloned from the Escherichia coli K-12 strain. A drug-sensitive strain of E. coli missing the main multidrug efflux pump AcrB was constructed as a host and the yddA gene was knocked out in wild-type (WT) and drug-sensitive E. coliΔacrB to study the yddA function. Sensitivity to different substrates of WT E.coli, E. coliΔyddA, E. coliΔacrB and E. coliΔacrBΔyddA strains was compared with minimal inhibitory concentration (MIC) assays and fluorescence tests. MIC assay and fluorescence test results showed that YddA protein was a multidrug efflux pump that exported multiple substrates. Three inhibitors, ortho-vanadate, carbonyl cyanide m-chlorophenylhydrazone (CCCP), and reserpine, were used in fluorescence tests. Ortho-vanadate and reserpine significantly inhibited the efflux and increased accumulation of ethidium bromide and norfloxacin, while CCCP had no significant effect on YddA-regulated efflux. The results indicated that YddA relies on energy released from ATP hydrolysis to transfer the substrates and YddA is an ABC-type multidrug exporter. Functional study of unknown ATP-binding cassette (ABC) superfamily transporters in the model organism E. coli is conducive to discovering new multidrug resistance-reversal targets and providing references for studying other ABC proteins of unknown function.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2018년도 추계학술대회
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• pp.113-113
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• 2018

Endophthalmitis is a disease that causes ocular inflammation and has a catastrophic effect on eyesight. Recent studies show that Enterococcus faecalis is rapidly increasing causative bacterium of endophthalmitis. It is predicted that the increased endophthalmitis by E. faecalis is presumable due to the high resistance of E. faecalis to moxifloxacin (MFX), which is a common antibiotic used for eye drop. Because of the need for therapeutic agents to overcome this problem, this study sought to explore the feasibility of developing a combination therapy using Orostachys japonicus. The ethylacetate fraction of O. japonicus (OJA) used in this study. Antimicrobial activity was tested 13 E. faecalis strains including one E. faecalis standard strain, eight clinically isolated E. faecalis strains and four quinolone resistant E. faecalis strains using CLSI antibiotic susceptibility test method. Minimal Inhibitory Concentration (MIC) of OJA was confirmed to be $500{\mu}g/ml$ for all 13 strains. Then we tested for the synergistic effect of OJA to MFX using checkboard test method. The MIC of MFX was $0.25{\mu}g/ml$ for the standard strain and 8 for the clinical isolates, and $16{\sim}64{\mu}g/ml$ for the quinolone - resistant strains. When OJA was mixed with MFX, no synergistic effect was observed in all strains, but the antibacterial activity of OJA remained unchanged. Most ocular other strains can be removed by MFX except the MFX resistant E. faecalis, which can be removed by OJA in combination therapy. Therefore, OJA can be a potential candidate for the combined treatment endophthalmitis.

• 한국수산과학회지
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• 제39권3호
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• pp.292-296
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• 2006

The antimicrobial activity of methanol extracts from 17 seaweeds was screened using a paper disc method and using three human skin pathogens: Staphylococcus aureus, S. epidermidis and Candia albicans. The serial extraction of Neorhodomela aculeata was also conducted using four different solvents (n-hexane, chloroform, ethyl acetate, and methanol) and the minimal inhibitory concentration (MIC) of each extract was examined for the three pathogens. Of the 17 seaweeds, the MeOH extracts of Ulva conglobata, N. aculeata and Symphyocladia latiuscula showed antimicrobial activities. For the extracts from N. aculeata and S. latiuscula, the inhibition zones were more than 10 mm in diameter against S. aureus and S. epidermidis, and >7mm for C. albicans. The inhibition zone of U. conglobata treatment was about 8 mm for S. aureus only. The MIC of each N. aculeata extract ranged from 8 to 32 mg/mL against the three human skin pathogens, and the lowest value (8 mg/mL was with the methanol extract. These results suggest that the MeOH extract of N. aculeata might be useful for developing new antibiotics against human skin pathogens.

• 자연과학논문집
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• 제8권2호
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• pp.49-55
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• 1996

현재 식품첨가물로 많이 사용되고 있는 유기산과 안정제 및 색소 등의 각종 세균과 Sacch. cerevisiae 에 대한 향균 특성을 조사하였다. 산도 조절용으로 사용되고 있는 젖산, 사과산, 호박산 및 주석산은 L. acidophilus와 Sacch. cerevisiae에 대하여 향균성이 없었으나 B. subtilis등의 세균에 대하여는 향균성이 있었고 특히 사과산은 P. aeruginosa에 대하여 강한 향균력이 있었다.(최소생육저지농도 : 0.05%). 안정제로서의 알긴산과 펙틴은 B. subtilis, E. coli, P. aeruginosa에 대하여 비교적 강한 향균성을 보였고 L. acidophilus에 대하여는 향균성이 없었다. 황색 색소(홍화엘로우)와 적색 색소(Red powder-N)는 향균성이 없었고 표백제인 $NaHSO_3$의 세균에 대한 최소생육저지농도는 0.05%, Sacch. cerevisiae에 대하여는 0.5%로 향균성이 있었다.