• KSBB Journal
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• 제13권4호
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• pp.383-390
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• 1998

Bacillus subtilis DT134 was resistant to 50-fold higher concentration of cadmium ions (Cd2+) than cadmium-sensitive B. subtilis BD224 in Luria Broth (LB) medium. Minimal inhibition concentration test in LB agar plates also showed similar results. The elevated cadmium resistance of B. subtilis DT134 strongly suggested a possible existence of cadmium resistance gene in it. Southern blot with Staphylococcus aureus cadA gene fragment (757 bp NlaIV-XmnI cadA DNA fragment) as probe was carried out to test the existence and similarity of the gene. In high stringency condition, there was no detectable signal, but in low stringency, a strong signal specific to the cadA probe could be detected. These results strongly suggested that there was some similarity between total DNA of B. subtilis DT134 and S. aureus pl258 in terms of cadmium resistance gene and the resistance mechanism might be an efflux mechanism. The subsequent efflux experiment showed that the cadmium resistance mechanism of B. subtilis DT134 was also due to the efflux of cadmium.

• Natural Product Sciences
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• 제13권2호
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• pp.164-168
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• 2007

To investigate natural antibiotics from plant essential oils and to evaluate their synergism with current antimicrobial drugs in inhibiting antibiotic-resistant strains of Streptococcus pneumoniae. The minimal inhibitory concentrations (MICs) of eleven plant essential oils and their main components were established for two antibiotic-susceptible and two antibiotic-resistant strains of S. pneumoniae, using broth microdilution tests. Potential synergism with oxacillin, norfloxacin, or erythromycin was evaluated using a checkerboard microtitre assay. Among the tested oils, Mentha piperita oil and its main component, menthol, exhibited the strongest inhibitory activities against all of the tested strains. The activity of antibiotics against antibiotic-resistant strains of S. pneumoniae was enhanced significantly by combination with Mentha piperita oils and its main component, menthol. In conclusion, the combination Mentha piperita essential oil or menthol with antibiotics could be used to reduce the effective dose of antibiotic and to modulate the resistance of S. pneumoniae strains.

• 한국임상수의학회지
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• 제15권1호
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• pp.30-35
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• 1998

Susceptibility or resistance of the Bordetella bronchiseptica was determined by using the broth microdilution method. Each Bordetella bronchiseptica was tested fur sutraceptluility with 7 different antimicrobial agents.4 high prevalence of resistance (greater than 80 %) was found when Bordetella bronchiseptica was tested with amikacin (AK), ciprofloxacin ILrJl gentamlcin IGAgf, kanamycin (Kbf) and tobramycin (TM). However, the Bordetella bronchiseptica were sensitive to chloramphenicol (CP) and tetracycline (TC). Three different combination of drug resistance were observed : AM-CF-GM-TM (1 strain), AM-CF-GM- KM-TM (45 strains), and AM-CF-GM-KM-TM-CP (3 strains). The MICs against Bordetella bronchiseptica were 0.13 to >2.00 for TC, 4 to >648 for CP, 8 to >128 for CF 16 to >256 for GM, 16 to >256 for TM, 32 to >256 for KM and 64 to 256 for AM.

• 미생물학회지
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• 제18권4호
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• pp.155-160
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• 1980

Microorgansims utilizing anionic detergent as their carbon and sulfur sources were isolated from soils and sewages. Alkyl benzene sulfonate (Hiti) and sodium dodecyl sulfonate (SDS) were the detergent compound tested. Three of these isolated microorganisms were identified as Pseudomonas spp. and the others asKlbsiella, Enterobacter and Acinetobacter. Biodegradation rate of the detergents and growth rate of Acinetobacter Strain II-8, Pseudomonas strain H-3-1 and 554 among six isolated microorganisms were investigated with colorimetric, warburg manometric, and ultraviolet absorption analyses. By performance of 4 serial successive tranfer to new culture broth for the purpose of adaptation method, ABS and SDS could be degraded to far more than 40%-60% and 70%-75%, respectively. However the employment of nonadaptation method, ABS and SDS were degraded to 30%-45% and 45%-65%, respectively. In another words, detergents degradation ability was increased to a certain extent by successive transfer to the new minimal media. We would conclude that the development of adaptation was effective in the removal of recalcitrant compounds.

• 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.

• 한국임상수의학회지
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• 제22권4호
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• pp.371-376
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• 2005

The aim of this study was to determine tile inhibitory effect of granitic powder against Microsporum canis. Fourteen strains of M. canis isolated from dgs and cats with fungal dermatitis and two strains isolated from humans were used in this study. The in vitro antifungal activities of granitic powder and 5 commercialized antifungal agents (terbinafine, itraconazole, ketoconazole, griseofulvin and fluconazole) were compared. The antifungal effect was measured by the broth microdilution method and was expressed as the minimal inhibitory concentration (MIC). The MIC value of the granitic powder was ranged from 31.3 to 250mg/ml. Terbinafine showed the lowest MIC value among the 5 commercial antifungal agents $(0.0078-0.125{\mu}g/ml)$, while fluconazole showed the highest MIC values $(125-1,000{\mu}g/ml)$. The MIC range of itraconazole, griseofuvin and ketoconazole were $0.125-0.5{\mu}g/ml\;0.625-5{\mu}g/ml$ and $10-40{\mu}g/ml$ respectively. The Geometric mean(GM) MIC values of terbinafine and ketoconazole against M. canis isolated from human were $0.0078{\mu}g/ml\;and\;10{\mu}g/ml$, respectively, while the GM MIC values of these agents against M. canis isolated from animals were $0.063{\mu}g/ml\;and\;31.4{\mu}g/ml$, respectively. Other antifungal agents did not show any significant differences in antifungal activity against M. canis of animal or human origin. Although granitic powder was shown to have antifungal activity, it was much lower than that of the 5 commercialized antifungal agents.

• 동의생리병리학회지
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• 제19권3호
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• pp.690-695
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• 2005

The purpose of this thesis is to dedicate to get the objectivity of herbal medicine treatments by choosing herbs likely to work as antifungal agents against Candida albicans which is the causes of Candida vaginitis, making experiments on them and getting the significant results. Each herb's efficacy on control the number of Candida vaginitis is noticed by using Disk Susceptibility test with six herbs medicine and Broth dilution assay of the culture. Cinamon Ramulus, Pulsatillae Radix, Dictamni Radicis Cortex, Paeoniae Radix, Arecae Semen, Artemisiae Capillaries Herba extracts experimented on the efficiency of antifungal activities against Candida albicans by disk susceptibility test. Pulsatillae Radix has the strongest efficiency. In Dictamni Radicis Cortex never appeared antifungal effect on treatment. MIC (minimal inhibition concentration) in vitro antifungal agents of Cinamon Ramulus, Pulsatillae Radix, Paeoniae Radix, Artemisiae Capillaries Herba extracts against Candida albicans was determined by broth dilution assay. MIC against Candida albicans is that Pulsatillae Radix is 2.5 mg/ml and Cinamon Ramulus is 5 mg/ml and Paeoniae Radix is 10 mg/ml and Artemisiae Capillaries Herba is 40 mg/ml.

• 한국임상수의학회지
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• 제25권5호
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• pp.346-354
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• 2008

The combined effects of EDTA-Tris and eighteen antimicrobial agents have been evaluated in eight clinically isolated methicillin-resistant bacteria (Staphylococcus aureus, Escherichia coli, Streptococcus uberis and Streptococcus agalactiae) from bovine mastitis. The antimicrobial activity was evaluated by measuring the minimal bactericidal concentration (MBC) for the antibiotics alone or in combination with EDTA-Tris in Mueller-Hilton broth and milk. Combined use of EDTA-Tris and antibiotics potentiated or antagonized activity of antibiotics against mastitic pathogens. Milk increased the antibiotic potency of erythromycin and spiramycin on S. aureus. Culture in milk changed patterns of EDTA-Tris combinational effects compared with that in standard Mueller-Hilton broth. Combined with EDTA-Tris in milk, synergic effects were observed in colistin, dihydrostreptomycin, kanamycin, erythromycin, gentamycin, oxytetracycline, streptomycin to E. coli, Str. uberis, and Str. agalactiae. However, significant antagonistic effects of milk on antibiotic susceptibility in combination with EDTA-Tris were noted in neomycin, streptomycin, penicillin, roxithromycin, and amoxicillin. This study indicates that combination therapy of EDTA-Tris with antibiotics in bovine mastitis should be used with caution because of the possible antagonistic effects of antibiotic combination with EDTA-Tris on mastitic pathogens. In addition, antibiotic susceptibility test in combination with EDTA-Tris in milk culture condition can be benefit in search of effective treatment regimen for some antibiotic-resistant bacteria of mastitis.

• Journal of Microbiology and Biotechnology
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• 제18권11호
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• pp.1762-1767
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• 2008

Image contrast of whole bacteria was compared in Staphylococcus aureus and Escherichia coli depending on pre-stain suspension liquids by energy-filtering transmission electron microscopy. The two bacterial strains were suspended in three most commonly used liquids for negative staining (triple distilled water [DW], phosphate-buffered saline [PBS], and nutrient broth [NB]) and directly observed without staining or stained with neutralized potassium phosphotungstate (PTA), respectively. Even though in low contrast, unstained bacteria were observed owing to their inherent electron density and cell shape in zero-loss (elastic scattering) images. After being suspended in PBS, unstained bacteria appeared to have higher contrast and more refined periphery than DW-suspended ones, and extracellular appendage structures such as fimbriae and flagella could be discerned. The unstained bacteria appeared to be invariably surrounded with electron-lucent precipitates, possibly from PBS. As far as delineation of the structures, the combination of DW or PBS suspension with subsequent staining provided the most satisfactory results, as evidenced by the high contrast of bacterial morphology and appendage structures. However, after being suspended in NB and stained with PTA, bacteria often had too high contrast or poor staining, with electron-dense aggregates around the bacteria. These results suggest that suspension with concentrated organic aliquots including broth media before PTA staining could deteriorate image contrast, and should be used only in dilute form for visualizing bacterial morphology and appendage structures. Moreover the contrast enhancement of unstained bacteria by salt granules would be advantageous in demonstrating bacterial sorption of environmental particles like heavy metals, maintaining minimal contrast for cell imaging.

• 한국미생물·생명공학회지
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• 제35권2호
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• pp.128-134
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• 2007

식물성장촉진 호르몬인 auxin, 식물병원성 진균의 생육을 억제하는 siderophore, 그리고 세포벽이 cellulose로 구성된 식물병원성 진균의 세포벽을 분해하는 cellulase를 동시에 생산하는 PGPR균주이자 생물방제균주로 선발된 Bacillus licheniformis K11이 생산하는 항진균성 siderophor의 특성을 확인한 결과 catechol type의 siderophore로 확인하였다. 또한 B. licheniformis K11의 siderophore 생산조건을 조사한 결과 nutrient broth(pH 9.0)를 $20^{\circ}C$에서 96 h 배양시 가장 많이 생산하였다. 그리고 탄소원과 질소원으로는 각각 trehalose와 $NH_4Cl$ 첨가시 siderophore를 가장 많이 생산하였다. 그리고 $siderophore_{K11}$의 정제는 Amberlite XAD-2과 sephadex LH-20 column chromatography를 통해 수행하였으며, HPLC를 통해 단일 물질임을 확인하였다. 정제된 $siderophore_{K11}$은 2, 3-dihydroxybenzoate의 유도체로 추정하며, P. capsici의 zoospores와 F. oxysporum의 conidia의 발아를 강하게 억제하였다.