• Korean Journal of Veterinary Research
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• v.41 no.2
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• pp.173-176
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• 2001

The present study was conducted to examine the drug susceptibility of 57 strains of Microsporum canis isolated from dogs with dermatitis in Taegu, 1999. Antifungal susceptibility test was performed by the microdilution method, using 7 antifungal drugs as follows: itraconazole(I), terbinafine(T), ketoconazole(K), griseofulvin(G), amphotericin B(A), flucytosine(5-Fc)(F), tolnaftate(To). All tester strains of M canis were highly susceptible to T, I, K and To(geometric mean $MICs{\leq}0.007{\sim}0.155{\mu}g/ml$), while those were lowly susceptible to G, A and F(geometric mean MICs $0.285{\sim}26.430{\mu}g/ml$).

• Journal of Life Science
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• v.9 no.3
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• pp.314-327
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• 1999

This study was investigated to isolate identify the total bacteria and fungi from the indoor air of work-place of the shoes, paint, stainless steel, and plastic industries. The number of bacterial colonies on the nutrient agar plates were calculated by the open petridish method for 30 minutes in indoor air of work-places at the autumn and winter. The isolated bacteria were identified by Gram stain and biochemical test using API Staph and API 20E kits. The isolated fungal colonies were identified by gross appearance of the giant colonies and microscopic examination of their spore and hyphal characteristics on the slide culture method. The minimum inhibitory concentration (MIC) of several antibiotics against isolated bacteria was determined by the microdilution method with Mueller-Hinton broth. The 70-400 colonies in autumn and 54-236 colonies in winter were isolated from the indoor air of work-places of several industry. The isolation rates of Gram positive cocci, Gram positive bacilli, Gram negative bacilli, and Gram negative cocci were 46.3%, 19.8%, 17.3%, and 16.1%, respectively. In Gram positive cocci, the most strains were identified as Aerococcus spp, Micrococcus spp, and Staphylococcus spp. In Gram positive and negative bacilli, and Gram negative cocci were identified as Bacillus spp, Pseudomonas spp, and Neisseria spp, respectively. The frequently isolated fungi were Aspergillus spp, Penicillium spp and Rhizopus spp, respectively. The frequently isolated Aerococcus spp, Micrococcus spp, and Staphylococus spp were highly resistance against ampicillin, erythromycin, methicillin, and tetracycline. These results arouse our attention to microbiologic pollution in the indoor air of work-places of industries.

• Journal of Microbiology and Biotechnology
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• v.18 no.3
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• pp.497-502
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• 2008

The essential oil from the cones of Pinus koraiensis was prepared after removing the seeds, and its chemical composition analyzed using gas chromatography-mass spectrometry (GC-MS). Hydrodistillation of the P. koraiensis cones yielded 1.07% (v/w) of essential oil, which was almost three times the amount of essential oil extracted from the needles of the same plant. Moreover, the antimicrobial activities of the oil against the growth of Gram-positive bacteria, Gram-negative bacteria, and fungi were evaluated using the agar disc diffusion method and broth microdilution method. Eighty-seven components, comprising about 96.8% of the total oil, were identified. The most abundant oil components were limonene (27.90%), ${\alpha}$-pinene (23.89%), ${\beta}$-pinene (12.02%), 3-carene(4.95%), ${\beta}$-myrcene (4.53%), isolongifolene (3.35%), (-)-bornyl acetate (2.02%), caryophyllene (1.71%), and camphene (1.54%). The essential oil was confirmed to have significant antimicrobial activities, especially against pathogenic fungal strains such as Candida glabrata YFCC 062 and Cryptococcus neoformans B 42419. Therefore, the present results indicate that the essential oil from the cones of Pinus koraiensis can be used in various ways as a nontoxic and environmentally friendly disinfectant.

• Korean Journal of Plant Resources
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• v.23 no.5
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• pp.436-444
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• 2010

Methanol extracts of the aerial and rhizome parts obtained from ten species of ferns has been screened for antimicrobial activities against Bacillus subtilis, Escherichia coli, Listeria monocytogenes, Propionibacterium acnes, Streptococcus mutans and Streptococcus sobrinus. Antimicrobial activities were carried out using broth microdilution method and paper disc diffusion assay and the extracts which showed clear zones more than 15mm in concentration of 2 mg/disc were tested for its antimicrobial activities at the $0.125{\sim}2\;mg{\cdot}mL^{-1}$ concentration of each extract for three days. The non-sterilized crude methanol extracts of Osmunda cinnamomea var. fokiensis rhizome showed the highest antimicrobial activities on B. subtilis(39%), E. coli (33%) and L. monocytogenes(58%) at the concentration of $2\;mg{\cdot}mL^{-1}$ after 72 hours. In P. acnes, frond extract of O. cinnamomea var. fokiensis showed most vigorous antimicrobial activities in the all extracts but it showed weak activity(clear zone diameters below 15 mm). All extracts has the antimicrobial activities on Streptococcus, but they exhibited weak activity. At the concentration of $2\;mg{\cdot}mL^{-1}$, only Osmunda japonica rhizome extracts showed 28 and 39% of antimicrobial activities on S. mutans and S. sobrinus after 72 hours and the other extracts showed below 10% of antimicrobial activities on S. mutans and S. sobrinus.

• 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.

• Journal of fish pathology
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• v.25 no.3
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• pp.181-188
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• 2012

The minimum inhibitory concentration (MIC) of eight antibiotics against Edwardsiella tarda 49 strains isolated from olive flounder (Paralichthys olivaceus) was determined by the broth microdilution method. E. tarda showed 38.8% and 61.2% resistance to ampicillin and amoxicillin. Both resistance rates of E. tarda were 4.1% against ciprofloxacin and norfloxacin. The $MIC_{50}$ values of oxytetracycline, amoxicillin and oxolinic acid were $64{\mu}g/ml$, $32{\mu}g/ml$ and $4{\mu}g/ml$. The $MIC_{50}$ value to ciprofloxacin was $0.25{\mu}g/ml$ which was lowest among eight antibiotics tested.

• Journal of The Korean Society of Integrative Medicine
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• v.6 no.3
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• pp.131-139
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• 2018

Purpose : The study objective was to assess the antibacterial activity of essential oil of basil against S. mutans and P. gingivalis and to explore its potential to prevent dental caries and peridontal disease. Method : Essential oil of basil, extracted using steam distillation, was diluted with triple distilled water and Tween 20 to generate samples at various concentration, that is 30%, 50%, and 70% (v/v). Strains of S. mutans and P. gingivalis were incubated in the medium under anaerobic condition. Broth microdilution susceptibility testing and plate incubation diffusion were utilized to determine the minimum inhibitory concentration (MIC) and to measure antibacterial activity, respectively. Result : An upsurge in antibacterial activity was seen to correlate with and increase in the concentration used for both bacterial strains, but was more significant with S. mutans. A statistically significant growth inhibition effect and reduction in the number of colonies was also observed with both strains dependent on the concentration used following 24 hours of incubation. Conclusion : Thus, the current study finding was that essential oil of basil was effective against dental caries and periodontal disease and could be used in dentifrice to help prevent oral disease.

• Journal of Veterinary Clinics
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• v.25 no.4
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• pp.231-235
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• 2008

Various kinds of antibiotic intramammary infusions are used for treatment of bovine mastitis. As antibiotic-resistant bacteria are increased, the therapeutic rate for bovine mastitis is decreased. The goal of this research is to detect significant synergic effects of combination of antibiotics with sulbactam, $\beta$-lactamase inhibitor, on methicilin-resistant Staphylococcus aureus (MRSA). We used 5 strains of MRSA isolated from bovine mastitis with clinical and subclinical signs. All of the bacteria isolated had resistance to oxacillin and showed multi-resistant patterns in the antimicrobial susceptibility tests. Minimal bactericidal concentrations of ampicillin, amoxicillin, cephalexin, ampicillin/sulbactam(2:1), amoxicillin/sulbactam (2:1), and cephalexin/sulbactam (1:1) were measured according to broth microdilution method suggested by National Committee for Clinical Laboratory Standards (NCCLS, M31-A2) to compare the synergic effects of sulbactam combination with each antibiotic alone. Ampicillin and amoxicillin showed synergic antibacterial activity to 4 and 3 respectively in 5 strains of MRSA in combination with sulbactam. This study demonstrates that ampicillin/sulbactam and amoxicillin/sulbactam can be therapeutic choices for mastitis associated with MRSA.

• International Journal of Oral Biology
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• v.33 no.4
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• pp.197-203
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• 2008

It has been reported that the antimicrobial susceptibility patterns of viridans streptococci vary according to geographical region. Although several studies on the antibiotic resistance of viridans streptococci in foreign countries have been reported, little is known about the distribution of resistance among viridans streptococci in Korea. In this study, 88 isolates of viridans streptococci from Korean students' dental plaque were identified as 12 different species. The susceptibility of these isolates to 8 antibiotics was investigated. The in vitro antibiotic activity of penicillin G, ampicillin, vancomycin, streptomycin, gentamicin, erythromycin, amoxicillin, and tetracycline was measured by the broth microdilution method. The range of the minimum inhibitory concentrations (MIC), MIC50, MIC90, and the percentage of the susceptible isolates were determined. Streptococcus mutans and Streptococcus salivarius were susceptible to the 8 antibiotics. Isolates with resistance to vancomycin, streptomycin, and amoxicillin were not found. The overall resistance rates of the 88 isolates to penicillin G, ampicillin, gentamicin, erythromycin, and tetracycline were 12.5%, 62.5%, 62.5%, 26.1%, and 26.1%, respectively.

• Korean Journal of Veterinary Research
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• v.56 no.2
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• pp.109-111
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• 2016

The present study was conducted to determine the antibiotic susceptibilities of local Mycoplasma hyopneumoniae (Mhp) and Mycoplasma hyorhinis (Mhr) filed isolates. Minimum inhibitory concentrations (MICs) of Mhp and Mhr field isolates (twelve each) obtained from enzootic pneumonia-like lung lesions during 2009-2011 from Korea were determined using the broth microdilution method. Tylvalosin showed the highest activity against Mhp and Mhr field isolates, with $MIC_{90}$ values of $0.06{\mu}g/mL$ and $0.12{\mu}g/mL$, respectively. Therefore, Korean Mhp and Mhr isolates are highly susceptible to tylvalosin.