• Journal of Veterinary Clinics
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• v.27 no.3
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• pp.252-256
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• 2010

Bovine mastitis, defined as an inflammation of the mammary gland, is usually associated with bacterial infection. Thus, treatment and control of mastitis relies primarily on antimicrobial therapy. This study investigated the bactericidal actions of silver ion against causing various bovine mastitis pathogens. Minimal inhibitory concentrations (MICs), minimum bactericidal concentrations (MBCs) and bactericidal activity times and concentrations of silver ion against pathogens were determined. The effect of silver ion on bacterial morphology was studied by scanning electron microscopy (SEM). The MICs and MBCs of silver ion for various bacteria strains ranged from 1.9-15.6 ${\mu}g$/ml. SEM images indicated formation of a pit, distortion and disruption of cell walls in silver treated Staphylococcus aureus and Escherichia coli. The results demonstrate that silver ion has a bactericidal capacity against causing various pathogens of bovine mastitis and suggest that silver ions may be exploitable as a therapeutic/preventative tool of bovine mastitis.

• Journal of the korean academy of Pediatric Dentistry
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• v.40 no.4
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• pp.241-246
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• 2013

The purpose of this study was to investigate the synergistic effects of erythrosine sensitized with a conventional halogen curing unit and sub-minimal bactericidal concentration(sub-MBC) of chorhexidine on bacterial viability of Streptococcus mutans in planktonic state. Sub-minimal bactericidal concentration of chlorhexidine was added into wells containing bacteria and erythrosine. The range of concentrations tested for chorhexidine was from 0.0000001% to 0.001%. The irradiation of the bacterial suspensions was performed for 15 sec with a conventional halogen curing unit light. In another set of experiment, the effects of 0.001% chlorhexidine were observed by adding chlorhexidine into wells containing the sub-minimal bactericidal concentration of erythrosine. At the concetration of 0.001% chlorhexidine, there were no antibacterial effects in the absence of erythrosine PDT(p < 0.05). At the concentraton of $1{\mu}M$ erythrosine, there was no photodynamic therapy effect in the absence of chlorhexidine(p < 0.05). But in the presence of sub-minimal bactericidal concentration of erythrosine with light exposure, the addition of 0.001% chlorhexidine increased the bactericidal rate(p < 0.05). A combination of erythrosine PDT with sub-MBC chlorhexidine resulted in a significant reduction in bacterial counts when compared to the case with the absence of chlorhexidine.

• Journal of the korean academy of Pediatric Dentistry
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• v.33 no.3
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• pp.447-456
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• 2006

In this study, the antimicrobial effects of Horseradish (Armoracia rusticana) root extracts against oral pathogens were investigated, and also compared with that of chlorhexidine. The following 7 microorganisms were used in this study, Streptococcus mutans ATCC 25175, Streptococcus sobrinus(d) ATCC 27607, Lactobacillus casei ATCC 393, Staphylococcus aureus ATCC 25923, Enterococcus faecalis ATCC 29212, Actinobacillus actinomycetemcomitans ATCC 29522. Candida albicans ATCC 10261. Horseradish root extracts and chlorhexidine were tested to determine their minimum inhibitory concentration(MIC) and minimum bactericidal concentration(MBC). The results of this study can be summarized as follows : 1. Horseradish root extracts showed antimicrobial effect against the tested oral pathogens. MIC and MBC of this extracts were 30-125, 125-500ppm, respectively. Especially, it was the most effective against C. albicans of other tested microorganisms. 2. Chlorhexidine also showed antimicrobial effect against the tested oral pathogens. MIC of chlorhexidine range between 0.15 and 2.5%, MBC are 0.4-2.5%. In conclusion, it was suggested that AIT had similar antimicrobial effects in the lower concentration, compared with that of chlorhexidine.

• Korean Journal Plant Pathology
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• v.12 no.3
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• pp.297-301
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• 1996

옥수수 깜부기병균에 대한 살균제 활성검정시 실내 검정과 온실 유묘검정과의 상관정도를 조사하기 위하여 5가지 살균제를 공시하여 실내와 온실에서 깜부기병균에 대한 억제효과를 비교하였다. 실내검정방법으로 사용한 최소생육억제농도법, 저지원법, 소생자발아검정법의 결과는 모두 온실유묘검정에서 얻어진 결과와 상관이 높았으며 특히 저지원법은 유묘검정결과와 매우 높은 상관관계를 보였다. 따라서 저지원법과 같은 실내검정방법은 대량의 활성검정시 간이검정방법으로 유용하게 이용될 수 있으리라 생각된다.

• Journal of Aquaculture
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• v.14 no.3
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• pp.157-163
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• 2001

The antibacterial effect of fish diet soaked in the extract of Salvia miltiorriza was tested to determine its levels of antibacterial activity, minimum inhibition concentration (MIC) and minimum bactericidal concentration (MBC). The extract showed strong activity against gram positive bacteria, but was weak against gram negative bacteria. Concentration levels of 13.4~40.3 and 67.2~403.0 $\mu\textrm{g}$/ml were determined as the MIC and MBC, respectively. However, levels above 403.0 $\mu\textrm{g}$/ml was neither bacteriostatic nor bactericidal against Edwardsiella tarta, a gram negative strain. The fish diet, soaked in the extract of Salvia miltiorriza, inhibited the growth of all strains of Streptococcus genus and Vibrio anguillarum. The relationship formula between weight of fish diet and Salvia miltiorriza extract absorbed into the fish diet was Y＝2.4953X＋3.3276 ($R^2$= 0.9999). The antibacterial activity of the fish diet, soaked in the extract, was stable from 10 to 35$^{\circ}C$ during the storage period of 28 days.

• Food Science of Animal Resources
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• v.30 no.3
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• pp.479-486
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• 2010

Tolerance against heat, sanitizers, and antibiotics of 112 Cronobacter isolates classified by desiccation was determined to permit effective biocontrol in powdered foods. The isolates were classified into three groups: dry-tolerant (n=37), dry-sensitive (n=7), and dry-intermediate (n=68). The strains that were highly tolerant to drying also showed high heat tolerance that they seemed to have high tolerance to heat after dry stress in powdered foods like infant formula. Sodium hypochlorite and benzalkonium chloride concentrations necessary to achieve a 5-log reduction in viable counts (CFU/mL) were 15-25 ppm and 5-15 ppm, respectively. However, there was little difference of the efficacy of these sanitizers between dry-sensitive and -tolerant strains for planktonic cells suspended in 3% albumin. The minimal inhibition concentration (MIC) of $\beta$-lactam ampicillin was 64-128 ppm for 90% of the strains. The isolates were consistently sensitive to kanamycin and naldixic acid (MIC=4 ppm). Dry-tolerant strains displayed more antibiotic resistance than dry-sensitive strains. The results indicate that dry-tolerant Cronobacter isolates often possess heat and antibiotic resistance, indicated the need for potent sterilization treatments of powdered foods.

• Journal of Oral Medicine and Pain
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• v.35 no.1
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• pp.19-29
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• 2010

Phytoncide, essential oil of trees, has microbicidal, insecticidal, acaricidal, and deodorizing effect. The present study was performed to examine the effect of phytoncide on Candida albicans, which is a commensal colonizer of the mucous membranes but has become an opportunistic pathogen. C. albicans was incubated with or without phytoncide extracted from Hinoki (Chamaecyparis obtusa Sieb. et Zucc.; Japanese cypress) and then changes were observed in its optical density, cell viability and morphology. As concentrations of phytoncide added to the culture medium increased, optical density and cell viability of C. albicans decreased. Minimum inhibitory concentration of phytoncide for C. albicans was observed to be 0.25%, and minimum fungicidal concentration was 0.5%. Numbers of morphologically atypical cells with electron-dense cytoplasm and granules and increased with increasing concentration of the phytoncide. At higher concentrations of phytoncide, compartments and organelles in the cytoplasm became indistinguishable. The overall results indicate that the phytoncide used for this study has a strong antimicrobial activity against C. albicans. Therefore, the phytoncide may be used as a candidate for prevention and therapeutic agent against oral candidiasis.

• Weed & Turfgrass Science
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• v.1 no.4
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• pp.69-75
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• 2012

In response of fungicides for control of gray snow mold, isolates of Typhula incarnata were collected from three golf courses in 2012 Yongpyeong, Korea and tested for sensitivity to propiconazole, tebuconazole and azoxystrobin fungicides. Four discriminatory concentrations were used to detect in vitro sensitivity of 50 isolates. Mean 50% effective concentration inhibiting mycelial growth ($EC_{50}$) values for tebuconazole was the lowest among the three fungicides. The $EC_{50}$ value of tebuconazole ranged from 0.0005 ${\mu}g\;ml^{-1}$ to 0.014 ${\mu}g\;ml^{-1}$ with a mean of 0.0048 ${\mu}g\;ml^{-1}$. The mean $EC_{50}$ values of propiconazole in triazole family was 0.5825 (0.78-1.651) ${\mu}g\;ml^{-1}$. $EC_{50}$ value of azoxystrobin ranged from 0.0017 ${\mu}g\;ml^{-1}$ to 0.131 ${\mu}g\;ml^{-1}$ with a mean of 0.0278 ${\mu}g\;ml^{-1}$. There was no correlation among $EC_{50}$ values for propiconazole, azoxystrobin and tebuconazole indicating no cross-resistance relationships with each other. Results of this study were confirmed no resistance isolates in vitro sensitivity of T. incarnata of three fungicides in Yongpyeong.

• Korean Journal Plant Pathology
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• v.11 no.2
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• pp.146-150
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• 1995

1994년, 1995년에 주요 채소 작물에서 분리한 잿빛곰팡이병균(Botrytis cinerea)의 방제 살균제에 대한 저항성을 조사한 결과, 1994년 분리된 713균주 중 610균주(85.6%)가 benzimidazole계에 저항성(Ben\ulcorner)이었고, 249균주(34.9%)는 dicarboximide계 살균제에 저항성(Pro\ulcorner)이었으며, benzimidazole계 및 N-phenyl carbamate계 두약제 모두에 저항성인 균주는 분리되지 않았다. 1995년에는 현재까지 520균주를 분리하였는데, 그중 Ben\ulcorner이 317균주(61%)이며 Pro\ulcorner은 214균주(41.2%)이었고, Ben\ulcorner이며 NPC\ulcorner인 균주(Ben\ulcorner+NPC\ulcorner)는 15균주(2.9%)로 나타났다. 이러한 저항성 균주의 최소 억제 농도는 carbendazim 1,000 $\mu\textrm{g}$/ml 이상, diethofencarb 1,000 $\mu\textrm{g}$/ml 이상이었다. 또 Ben\ulcorner+NPC\ulcorner인 15균주 중 3균주는 dicarboximide계 살균제인 procymidone에도 저항성이었으며, 한 균주를 제외한 모든 Pro\ulcorner 균주는 Ben\ulcorner로 나타났다.

• Journal of the korean academy of Pediatric Dentistry
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• v.46 no.2
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• pp.135-138
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• 2019

The aim of this study was to investigate the susceptibility of Mutans streptococci in both planktonic and biofilm states to erythrosine. S. mutans was cultured in brain-heart infusion (BHI) broth. Erythrosine was diluted in BHI broth and prepared at a concentration range of $0.02-10000{\mu}g/L$. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were measured using the microdilution method. After forming biofilms on 96-well plates, the minimum biofilm inhibitory concentration (MBIC) and minimum biofilm eradication concentration (MBEC) were measured. S. mutans was susceptible to erythrosine in both planktonic and biofilm states. MIC and MBC values were both $19.5{\mu}g/L$ for the planktonic state, while MBIC and MBEC values were $313{\mu}g/L$ and $2500{\mu}g/L$, respectively, for the biofilm state. Erythrosine ($19.5{\mu}g/L$) exhibited a bactericidal effect on S. mutans (killing 99.9%) in the planktonic state. For biofilms, erythrosine inhibited biofilm growth and eradicated 99.9% of biofilm bacteria at higher concentrations than MIC and MBC. These MBIC and MBEC concentrations are much lower than known noxious doses, and the MIC, MBC, and MBIC values were even lower than clinical concentrations.