• Korean Journal of Food Science and Technology
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• v.49 no.2
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• pp.146-150
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• 2017

Staphylococcus aureus is a pathogenic bacterium that causes food poisoning, exhibits a strong capacity to form biofilm, and is highly resistant to antimicrobial agents. The purpose of this study was to investigate the antimicrobial characteristics of corosolic acid against S. aureus. S. aureus showed high susceptibility to corosolic acid in a concentration-dependent manner. The minimum inhibitory concentration and colony-forming ability determined by the broth microdilution method showed that corosolic acid had strong antimicrobial activity against the bacteria. The diameters of the inhibition zone and numbers of colony forming units at each concentration of corosolic acid were also measured. In addition, corosolic acid displayed potent biofilm inhibition activity against S. aureus at concentrations below its minimum inhibitory concentration. These results suggest that corosolic acid can be used to effectively prevent biofilm formation by S. aureus, thereby making S. aureus more susceptible to the action of antimicrobials.

• Microbiology and Biotechnology Letters
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• v.27 no.3
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• pp.179-183
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• 1999

The volatile components (essential oil) showing antimicrobial activity were extracted from the fruit peel of Zanthoxylum piperitum DC by distillation and separated by thin layer chromatography (TLC). The crude volatile components exhibited antimicrobial activity only at very high concentration. The active fraction obtained by TLC inhibited noticeably the growth of bacteria. The minimum inhibitory concentration (MIC) of the fraction were 150ppm, 300ppm, and 300ppm against Escherichia coli, Staphylococcus aureus, and Salmonella enteritidis, respectively. The components in the active fraction were identified by gas chromatography/mass spectrometry to be geranlyl acetate (60.23%), citronellal(36.01%), citronellol(3.77%), geraniol(0.46%), and cumin ldehyde(0.43%).

• Journal of Applied Biological Chemistry
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• v.49 no.4
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• pp.131-134
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• 2006

The in vitro anti-fungal activity of hydroxylated fatty acids obtained from microbial conversion by Psuedomonas aeruginosa PR3 using ricinoleic acid(RA), eicosadienoic acid(EDA) and conjugated linoleic acid(CLA) as substrates, was investigated. Bioconverted hydroxylated fatty acids showed different anti-fungal activities potentials against the range of phytopathogenic fungi such as Botrytis cinerea, Rhizoctonia solani, Fusarium oxysporum, Sclerotonia sclerotiorum, Colletotricum capsici, Fusarium solani and Phytophthora capsici. RA and EDA showed up to 50% fungal mycelial inhibition at the concentration of $5{\mu}l\;ml^{-1}$. RA, EDA and CLA also exhibited anti-fungal activities with minimum inhibitory concentration(MIC), ranging from 500 to $1000{\mu}g\;ml^{-1}$. Screening was also carried out using varied concentrations of bioconverted RA and EDA for determining the anti-fungal effect on the spore germination of different fungi. Bioconverted RA and EDA showed a considerable degree of spore germination inhibition.

• Food Science of Animal Resources
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• v.22 no.1
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• pp.66-71
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• 2002

As extraction solvent, ethanol fraction was revealed the highest anti-microbial activities. The butanol, ethyl acetate and chloroform fractions were also revealed anti-microbial activities with less extent compared to ethanol fraction. All fractions exhibited to inhibition of bacterial growth regardless gram positive and negative, yeast and fungi, however, was not exhibited effectively to their growth. In the inhibition activities against E. coli, the complete inhibition concentration of Yecheon propolis were at 0.40mg/ml, respectively. Complete inhibition concentration of Youngwol was revealed at 0.25mg/ml after 12 hours incubation. In the inhibition activities against P. aeruginosa, the complete inhibition concentration of Youngwol propolis wat at 0.20mg/ml. Yecheon propolis was reveraled the inhibition at 0.20mg/ml after 12 hours incubation. In the inhibition activities against S. typhimurium, the complete inhibition concentration of Youngwol propolis was at 0.20 and 0.25mg/ml and Yecheon was 0.40mg/ml. The Minimum Inhibitory Concentration (MIC) of ethanol extraction fraction of Yecheon propolis to P. aeruginosa, S. aureus, and S. typhimurium were > 0.2, 0.25, 0.25 and 0.4∼>0.5mg/ml, and of Youngwol propolis to P. aeruginosa, E. coli, S. aureus, S. typhimurium, B. subtlis and C. utilis were 0.15, 0.25, 0.25, 0.3 and 0.4mg/ml, respectively.

• Herbal Formula Science
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• v.25 no.4
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• pp.449-456
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• 2017

Objective : Coptis rhizoma is traditional herb in Korean medicine, and Pelargonium sidoides extract has been used for relief of acute bronchitis in Western medicine. The present study examined the antibacterial effect of fusion formulation of Coptis rhizoma extract and Pelargonium sidoides extract against bronchial diseases bacteria. Methods : Test sample, fusion formulation of Korean and Western medicine, was prepared by mixing Coptis rhizoma extract and Pelargonium sidoides extract at a ratio of 1:2 (w/w). Antimicrobial properties of test sample were determined by agar diffusion assay and minimum inhibitory concentration (MIC) against bronchus diseases bacteria. Results : In agar diffusion assay, the highest amount of test sample (4 mg/disk) exhibited antibacterial activity against all microorganisms tested. Test sample showed the high activity for S. aureus (19.5 mm), C. diptheriae (16.5 mm), A. fumigatus (19.3 mm), F. nucleatum (22.7 mm) and Mycobactrium sp. (17.3 mm), whereas it showed a low activity for K. pneumonia (9.7 mm). The MIC value was determined as $250{\mu}g/m{\ell}$ against C. diptheriae. Test sample showed better growth inhibitory effects against S. aureus and A. fumigatus with the MIC valus of $125{\mu}g/m{\ell}$. Conclusion : These results suggest the possibility of application to chronic respiratory diseases of fusion formulation of Korean and Western medicine, which was prepared with Coptis rhizoma extract and Pelargonium sidoides extract.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.24 no.3
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• pp.17-26
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• 2011

Objectives : Corydalis tuber has been used for promoting blood circulation and for relieving pain in Oriental medicine. In the present study, we focused on the antimicrobial activity of Corydalis tuber and compared its antimicrobial activity with the processed Corydalis tuber. Methods : Processing of Corydalis tuber was accomplished by immersing in 5% of acetic acid for 12 h and then by roasting at $250^{\circ}C$ for indicated time periods(0-30 min). Minimum inhibitory concentration(MIC) and the zone of growth inhibition were determined against Propionibacterium acnes(P. acnes). Results : The methanolic extracts of Corydalis tuber showed potent antimicrobial effect(MIC 62.5 ${\mu}g/ml$). Its alkaloidal component, dehydrocorydaline, also exhibited antibacterial activity(MIC 25.0 ${\mu}g/ml$). After processing of Corydalis tuber, its inhibitory effect on the growth of P. acnes was significantly enhanced compared with that of unprocessed Corydalis tuber. Furthermore, elevated content of dehydrocorydaline was found in the processed than the unprocessed Corydalis tuber. However, the different roasting minutes effected on antimicrobial activity. The best roasting time of Corydalis tuber was 10 min, while roasting for the time above 15 min resulted in diminishing antimicrobial activity. Thus, it was concluded that the standardized processing condition of Corydalis tuber should be established to obtain enhanced antimicrobial(P. acnes) activity. Conclusion : For antimicrobial effect against P. acnes, the best processing condition of Corydalis tuber is immersing in 5% of acetic acid for 12 h and by roasting at $250^{\circ}C$ for 10 min.

• The Journal of the Korea Contents Association
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• v.19 no.1
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• pp.242-255
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• 2019

In this study, we examined the antimicroboal effect against Actinobacillus actinomycetemcomitans and Prevotella intermedia which were the bacteria causing the Periodontopathic by using 34 types of natural plant extracts. Therefore, this study measures growth inhibition activity and Minimum Inhibition Concentration (MIC) of a sample extract with the use of organic solvent extracts in order to analyze the antibacterial effect of natural plant extracts on periodontopathic bacteria. Each of the 34 types of natural plant extracts were extracted by using the ethanol, and subsequently, the size of growth inhibition zone(clear zone, ㎜) of respective extracts were measured through the disk diffusion method. As a result, it was found that the growth inhibitory activity was found for A. actinomycetemcomitans, which is the bacteria causing the Periodontitis, in 13 types of natural plant extracts such as Raphanus sativus, Akebia quinata, Paeonia lactiflora, Belamcanda chinensis, Inula britannics, Houttuynia cordata, Forsythia saxatilis, Gentiana macrophylla, Melia azedarach, Scutellaria baicalensis, Coptis chinensis, Phellodendron amurense, Kalopanax Pictus, etc. In the case of P. intermedia, the growth inhibitory activity was found in 13 types of natural plant extracts such as Raphanus sativus, Angelica acutiloba, Akebia quinata, Belamcanda chinensis, Inula britannics, Houttuynia cordata, Cinnamomum cassia, Aster tataricus, Melia azedarach, Scutellaria baicalensis, Coptis chinensis, Phellodendron amurense, Kalopanax Pictus etc. For A. actinomycetemcomitans, anti-bacterial effect was exhibited in Belamcanda chinensis, Cinnamomum cassia, Kalopanax Pictus, Phellodendron amurense, Coptis chinensis. The Coptis chinensis showed the most excellent growth inhibitory activity in all organic solvent fragment, while P. intermedia showed the growth inhibitory activity in Belamcanda chinensis, Cinnamomum cassia, Meliaazedarach, Phellodendron amurense, and Coptis chinensis.

• Journal of Food Hygiene and Safety
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• v.39 no.1
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• pp.1-8
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• 2024

Salmonella is widely prevalent in various environments and often detected in poultry. In this study, we investigated the effect of heat treatment on heat resistance via measuring the minimum inhibitory concentration (MIC) values of antibiotics after 3, 6, and 9 min of acclimatization to mild heat treatment (50℃) against 11 strains of Salmonella spp. Most strains were susceptible to chloramphenicol and their MIC values were maintained or decreased after heat treatment compared to the control. Most control and heat-treated strains showed susceptibility or intermediate resistance to ciprofloxacin. All isolates were susceptible to tetracycline, with the MIC increasing after heat treatment for S. Gaminara BAA 711. In the control, three, two, and six strains were susceptible, intermediate resistance, and resistant to gentamicin, respectively. Among them, S. Heidelberg ATCC 8326 had an intermediate MIC breakpoint of 8 ㎍/mL in the control; however, after 3 and 9 min of heat treatment, the MIC value increased to 16 ㎍/mL, indicating it to be resistant. The results of this study revealed the changes in antibiotic resistance in some of the 11 strains after heat treatment. MIC values of ciprofloxacin increased when S. Montevideo BAA 710 was heat treated for 3 and 6 min. MIC values of gentamicin increased after 3 min of heat treatment for S. Enteritidis 109 D1 and after 3 and 9 minutes of heat treatment for S. Heidelberg ATCC 8326. The MIC value of tetracycline increased when S. Gaminara BAA 711 was heat treated for 6 and 9 min.

• Korean Journal of Clinical Laboratory Science
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• v.45 no.1
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• pp.21-25
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• 2013

Acinetobacter baumannii is an aerobic, gram-negative and glucose-non-fermenting bacterium, which has emerged as a serious opportunistic pathogen. Many clinical microbiology laboratories use the Vitek 2 system for the routine antimicrobial susceptibility testing process, including testing on A. baumannii isolates. However, in case of amikacin, it is now recommended to perform additional antimicrobial susceptibility testing for A. baumannii strains due to the relatively lower minimum inhibitory concentration (MIC) in the Vitek 2 system compared to conventional reference methods. In our study, we assessed MIC for amikacin susceptibility testing of A. baumannii isolates in the Vitek 2 system, the agar dilution, Etest, and disk diffusion method. We collected 40 gentamicin-resistant, A. baumannii strains (amikacin MIC by Vitek 2:${\leq}2{\mu}g/mL$, 2 isolates; $4{\mu}g/mL$, 34 isolates; $8{\mu}g/mL$, 4 isolates) from a University hospital and compared the Vitek 2 system to other reference methods for testing susceptibility to amikacin. The Vitek 2 system showed major errors in all of the 40 isolates, yielding a low MIC. The results of our study strongly suggested that the Vitek 2 system was not a reliable method to test the MICs of gentamicin; ranging from ${\geq}16{\mu}g/mL$ for amikacin susceptibility. Other tests, such as agar dilution, Etest, or disk diffusion methods, should be paralleled to determine the MIC of amikacin in A. baumannii.

• Journal of the East Asian Society of Dietary Life
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• v.9 no.2
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• pp.214-222
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• 1999

Prunus mume has been used for the folk medicine by many old civilizations to treat food-borne diseases or enteric disorders. The purpose of this study was to investigate the antimicrobial activity of beverages containing Prunus mume extracts against Staphylococcus aureus, Shigella dysenteriae, Shigella flexneri, Shigella sonnei, Escherichia coli and Pseudomonas aeruginosa. Seven different types of Prunus mume extracts containing beverages have been prepared for the test in which minimum inhibitory concentration for each microorganism has been determined by serial dilution method using either TSA or TSB medium. Pseudomonas aeruginosa showed least resistance and 0.3g/$m\ell$ concentrations of 5% Prunus mume extracts containing beverage had antimicrobial property against the organism. Beverages containing more than 15% of Prunus mume extracts showed antimicrobial activity against all tested microorganisms at the MIC value of less than 0.25g/$m\ell$. The effect of Prunus mume on the growth of food-borne pathogens has been also studied using a spectrophotometer. In the growth assay, each of the Prunus mume extracts containing beverage was added to the medium at the concentration of 25% (v/v). Beverage containing 20% Prunus mume extracts showed inhibitory effect on the growth of all tested microorganisms.