• International Journal of Oral Biology
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• v.39 no.2
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• pp.115-120
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• 2014

Minimal inhibitory concentration (MIC) is the lowest concentration of antibiotics that inhibits the visible growth of a microorganism. It has been reported that sub-MIC of antibiotics may result in morphological alterations along with biochemical and physiological changes in bacteria. The purpose of this study was to examine morphological changes of periodontal pathogens after treatment with sub-MIC antibiotics. Aggregatibacter actinomycetemcomitans, Fusobacterium nucleatum, and Porphyromonas gingivalis were used in this study. The MIC for amoxicillin, doxycycline, metronidazole, penicillin, and tetracycline were determined by broth dilution method. The bacterial morphology was observed with bright field microscope after incubating with sub-MIC antibiotics. The length of A. actinomycetemcomitans and F. nucleatum were increased after incubation with metronidazole; penicillin and amoxicillin. P. gingivalis were increased after incubating with metronidazole and penicillin. However, F. nucleatum showed decreased length after incubation with doxycycline and tetracycline. In this study, we observed that sub-MIC antibiotics can affect the morphology of periodontal pathogens.

• Journal of Veterinary Clinics
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• v.23 no.3
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• pp.286-290
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• 2006

To find alternative agents for bovine mastitis, the extracts of 30 selected herbal medicine were screened for their antibacterial activity against mastitis pathogens. The extracts of 9 herbal medicine, Terminaliae chebula, Cinnamonum loureirii, Paeonia japonica, Inula britannica, Caesalpinia sappan(C. sappan), Salix babylonica, Alpinia katsumadai, Polygonum aviculare and Coptidis japonica showed strong antibacterial activity. Among of them, C. sappan extract was found to be the most active against all bacteria in this experiment. Methanol extract of C. sappan and brazilin, the main component of C. sappan, had inhibitory activity against a variety of pathogens, however they had less of an inhibitory effect on gram negative bacteria. Minimal inhibitory concentrations of brazilin against gram positive pathogens was lower than that of methanol extract. These results showed that the extract of C. sappan has a potential as a therapeutic agent for bovine mastitis.

• Archives of Pharmacal Research
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• v.17 no.6
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• pp.438-442
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• 1994

Antimicrobial activity of GL (the aqueous extract from the carpophores of Ganoderma lucidum ($F_RK_{KARST}$) was tested in vitro aginst Gram positive and Gram negative bacteria by serial broth dilution method, and the antimicrobial activity was expressed by minimal inhibitory concentration (MIC). Among fifteeen species of bacteria tested, the natimicrobial activity of GL was of antimicrobial combinations of GL with four kinds of antibiotics (ampicilin, cefazolin, oxytet-racycline and chloramphenicol), the fractional inhibitory concentraction index (FICI) was determined by checkerboard assy for each stain. The antimicrobial combinations of GL with four antibiotics resulted in additive effect in most instances, synergism in two instances, and antagonism in two instances. Synergism was obversed when GL was combined with cefazolin against Bacillus subtilis and Klebsiella oxytoca.

• Journal of Periodontal and Implant Science
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• v.33 no.3
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• pp.341-348
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• 2003

The purpose of this study was to determine the minimal inhibitory concentration (MIC) of cefuroxime axetil,　semisynthetic cefalosporin, for some putative periodotopathogens; F. nucleatum, A. actinomycetemcomitans P. intermedia and P. gingivalis. To investigate the efficacy of cefuroxime axetil, several antibiotics, amoxicillin, metronidazole, and ciprofoxacine, were used as control. The MIC was measured by Murray' s method. The MIC of cefuroxime axetil against some putative microbes, as a single use regimen, was relatively high in comparison with that of the other antibiotics used in this study. The MIC of cefuroxime axetil/metronidazole against some putative microbes, as a simultaneous regimen, was similar to that of the other antibiotics used in this study. The manimal level of cefuroxime concentration in gingival fluid was 9${\mu}$/ml at 36hr after the first dose. In conclusion, within the limited experiment, metronidazole/ cefuroxime axetil therapy of periodontitis may provide a therapeutic benefits in reducing the periodontopathogens.

• YAKHAK HOEJI
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• v.36 no.5
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• pp.407-411
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• 1992

As part of our search for less toxic antimicrobial substances from natural resources, naringin was isolated from feels of Citri fructus and then hydrolyzed to naringenin. The antimicrobial activity of naringenin was examined by measuring the minimal inhibitory concentration(MIC) against fourteen species of bacteria. The antimicrobial activity of narngenin in combination with rutin or hesperetin was evaluated by checkerboard method. Among fourteen species tested, the antimicrobial activity of naringenin was the most prominant against Staphylococcus aureus and Shigella boydii showing MIC of $100\;{\mu}g/ml$ for both species. Combinations of naringenin with rutin or hesperetin showed synergism against several species of bacteria, but no antagonism was observed.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.20 no.1 s.32
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• pp.195-200
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• 2007

Objective : This experimental study was performed to investigate the effect of Jinpi-san on Staphylococcus aureus(S. aureus) and Staphylococcus epidermidis(S. epidermidis) that induce keratitis. Methods : Minimal inhibitory concentration(MIC) was measured by dropping to $50{\mu}l$ according to density Jinpi-san(100%, 10%, 1%, 0.1 %). Anti-bacterial potency was measured by the size of inhibition zone with change of volume. Results : 1. MIC on S. aureus in Jinpi-san was $40{\mu}l$ undiluted solution. 2. MIC on S. epidermidis in Jinpi-san was $20{\mu}l$ undiluted solution. Conclusions : These results indicate that Jinpi-san can be used to cure S. aureus, S. epidermidis that induce eye disease(keratitis). If further study is performed, the use of eye drops will be valuable and beneficial in the clinical medicines.

• Journal of Environmental Health Sciences
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• v.35 no.3
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• pp.178-186
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• 2009

Rice straw liquid was prepared from rice straw using simple pyrolysis furnace, and its effects on plant growth and antibiosis were investigated. Effects of straw liquid on plant growth of Oryza sativa L., Glycine max Merr. and Lactuca sativa L. and antibiosis of bacteria and mold of rice straw liquid were studied. Th rice straw liquid showed good results on plant growth and multiplication. Rice straw liquid showed a little antibiosis on bacteria but non antibiosis on mold. Rice straw liquid had minimal inhibitory concentration of 2.5-5% for bacteria.

• Biomedical Science Letters
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• v.3 no.1
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• pp.49-54
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• 1997

Meanwhile Pityrosporum species as well as Candida species in yeast phase are not pathogenic, Pityrosporum in mycelial phase is pathogenic. Pityrosporum species can be isolated not only from tinea versicolor patients but also from ninety (90) percent of healthy persons. Minimal inhibitory concentration (MIC) of ketoconazole against Pityrosporum spp. was 0.05~0.8$\mu\textrm{g}$ ml$^{-1}$and the MIC of ketoconazole was the lowest. Of itraconazole, selenium sulfide, sodium thiosulfate and ketoconazole had the lowest MIC against P. orbiculare. The P. orbiculare strains isolated from healthy persons were inhibited by lower MIC than those isolated from tinea versicolor patients. P. ovale strains were inhibited by lower MIC at MIC$_{50}$ and MIC$_{90}$ of oral and topical antifungal agents than p. orbiculare.

• Mycobiology
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• v.29 no.1
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• pp.11-14
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• 2001

A preparation of water soluble components(EA) was made from carpophores of Elfvingia applanata(Pers.) Karst and its in vitro antibacterial activity on a number of bacterial species was examined by macrobroth dilution assay. Among 16 species of bacteria tested, the most potent antibacterial activity was observed against Staphylococcus epiderrnidis and Proteus vulgaris, of which MICs were 1.25 mg/ml. To investigate the antibacterial effects in combinations of EA with quinolone antibiotics, such as ciprofloxacin, enoxacin, lomefloxacin, norfloxacin, and ofloxacin, the fractional inhibitory concentrations(FICs) and the fractional inhibitory concentration indices(FICIs) for four bacterial strains were determined by macrobroth dilution checkerboard assay. Combinations of EA and quinolones exhibited either additive or indifferent effects of antibacterial activity in most instances. However, both synergistic and antagonistic effects were not observed in any cases.

• Journal of Food Hygiene and Safety
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• v.7 no.2
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• pp.99-106
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• 1992

To prevent food-poisoning outbreaks by Vibrio vulnificus the antimicrobial efficacy of grapefruit seed extract (GFSE) was examined. Minimal inhibitory concentration (in vitro) for the microorganism was found to be 50∼100 ppm. Transmission electron micrographs of Vibrio vulnificus showed the biocidal action of this natural antimicrobial agent would be related to specific respiratory effect coupled with the destruction of permeable function of microbial cell membrane. After Anguilla japonica GFSE-injected to the body was incubated in the seawater contaminated by Vibrio vulnifiucs the fish meats were taken up, mixed with control diet and used as a diet in the feeding experiment. In this experiment the effect of GFSE treated with fish muscle on body weight, protein efficiency ratio, serum enzymes and serum blood components of broiler chicks was investigated. It is proved from this study that there is neither Vibriosis nor toxicity associated with GFSE itself an fish meats treated with it when it is injected to the fish body at a level of 250 ppm or less.