• Korean Journal of Veterinary Service
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• v.40 no.2
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• pp.101-105
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• 2017

The purpose of this study was to investigate prevalence and antimicrobial resistance patterns of Campylobacter spp. from duck feces in northern area of the Gyeongnam province, Korea. Samples of 121 duck feces were taken from April to December 2014 for this survey. Samples were examined by bacteria isolation and reverse transcriptase-polymerase chain reaction assay for detection of Campylobacter spp. Campylobacter were isolated in 37 samples (30.6%). Among these samples, C. jejuni and C. coli were isolated in 35 samples and 2 samples, respectively. Minimum inhibitory concentration (MIC) test is performed to investigate antimicrobial resistance patterns of Campylobacter spp. C. jejuni were resistant to ciprofloxacin (85.7%), nalidixic acid(82.9%), tetracycline (77.1%), gentamicin (57.1%), azithromycin (40.0%), clindamycin (34.3%), erythromycin (22.9%), and florfenicol (8.6%). These data support a database of pollution and antimicrobial resistance of Campylobacter spp. from duck feces and provide a basic information of reducing the secondary damage of antibiotic misuse.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2010.10a
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• pp.16-16
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• 2010

본 연구는 13과 37종 양치식물의 엽상체(지상부)와 근경의 메탄올 추출물을 대상으로 식품의 오염 및 변질의 원인이 되는 Bacillus subtils, 식중독의 원인이 되는 Escherichia coli, 식중독 및 선회병(listeriosis)의 원인이 되는 Listeria monocytogenes, 피부 여드름의 원인이 되는 Propionibacterium acnes에 대한 항균활성을 탐색하고 항균력이 우수한 천연소재를 선발하기 위하여 시행하였다. $5mg{\cdot}mL^{-1}$의 농도의 추출물을 대상으로 각 미생물에 대하여 50% 이상의 항균활성을 나타낸 양치식물 추출물을 선발하였으며, 선발된 추출물을 2mg/disc의 농도로 조절하여 agar diffusion법으로 항균력을 측정하여 15mm 이상의 억제환을 나타내는 추출물을 선발하였다. 상기의 방법으로 선발된 추출물을 $0.125{\sim}2.000mg{\cdot}mL^{-1}$의 농도로 조절하여 72시간 동안 각 미생육의 생육에 미치는 영향을 분석하여 항균활성이 우수한 양치식물의 추출물을 선발하였다. 연구의 결과, B. subtils의 생육억제에는 야산고비의 성엽과 쇠고비의 근경 추출물, E. coli의 생육 억제에는 설설고사리의 성엽과 나도히초미 및 더부살이고사리의 근경 추출물, L. monocytogenes의 생육억제에는 관중의 성엽과 공작고사리, 꿩고비 및 쇠고비의 추출물이 효과적이었다. 한편 대부분의 양치식물 추출물은 P. acnes의 생육억제 효과가 미비하였으나, 관중과 참지네고사리는 성엽과 근경 모두에서 P. acnes의 생육억제 효과가 매우 우수하였으며, 별도의 제균처리를 하지 않은 관중과 참지네고사리의 메탄올 조추출물의 $MIC_{50}$은 성엽의 추출물에서 66.8과 $80.4{\mu}g{\cdot}mL^{-1}$, 근경의 추출물에서는 8.8과 $54.2{\mu}g{\cdot}mL^{-1}$로 나타났다.

• International Journal of Oral Biology
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• v.39 no.2
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• pp.87-95
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• 2014

The purpose of this study was to isolate and identify bacteria from the 4 patients with non-odontogenic infectious lesions (mucormycosis, chronic inflammation from wound infection, and two actinomycosis) and determine their antimicrobial susceptibility against eight antibiotics. Bacterial culture was performed under three culture conditions (anaerobic, $CO_2$, and aerobic incubator). The bacterial strains were identified by 16S rRNA gene (16S rDNA) sequence comparison analysis method. For investigating the antimicrobial susceptibility of the bacteria against eight antibiotics, penicillin G, amoxicillin, tetracycline, cefuroxime, erythromycin, clindamycin, vancomycin, and Augmentin$^{(R)}$ (amoxicillin + clavulanic acid), minimum inhibitory concentration (MIC) measurement was performed using broth microdilution assay. Nosocomial pathogens such as Enterococcus faecalis, Klebsiella pneumoniae, Bacillus subtilis, and Neisseria flavescens were isolated from mucormycosis. Veillonella parvula, Enterobacter hormaechei, and Acinetobacter calcoaceticus were isolated from chronic inflammatory lesion. Actinomyces massiliensis was isolated from actinomycosis in parotid gland. Capnocytophaga ochracea was isolated from actinomycosis in buccal region in anaerobic condition. There was no susceptible antibiotic to all bacteria in mucormycosis. Tetracycline was susceptible to all bacteria in chronic inflammation. C. ochracea was resistant to vancomycin and penicillin G; and other antibiotics showed susceptibility to all bacteria in actinomycosis. The results indicated that the combined treatment of two or more antibiotics is better than single antibiotic treatment in mucormycosis, and penicillin is the first recommended antibiotic to treat actinomycosis.

• Food Science and Preservation
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• v.16 no.5
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• pp.759-764
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• 2009

The antimicrobial activities of extracts of Prunus mume by sugar against food poisoning bacteria, and the effects of heat and pH treatment on these antimicrobial activities, were investigated. The level of total solids, pH, and acidity of P. mume extracts were 55.08% (w/w), pH 3.1, and 1.52%, respectively. P. mume extracts showed the strongest antimicrobial activity against Vibrio parahaemolyticus, among the bacteria tested. P. mume extracts significantly inhibited the growth of V. parahaemolyticus, Bacillus cereus, and Staphylococcus aureus at levels of 1-2% (w/v) of extracts in media. The antimicrobial activities of P. mume extracts were neither affected by heating at $65-125^{\circ}C$ for 30 minutes, nor by neutralization of extract to pH 7.0.

• YAKHAK HOEJI
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• v.54 no.2
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• pp.106-111
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• 2010

The chemical structures of eight compounds purified from two plants (Polygala tenuifolia Willdenow and Dioscorea batatas Decene) were determined and their anti-microbial activity against three microbial strains (Staphylococcus aureus, Pseudomonas aeruginosa, and Candida albicans) was tested. The three micro organisms were cultured in 96-well plates or Petri dishes without (control) or with the eight compounds added at concentrations of 100 to 0.01 ${\mu}M$ (wt/vol). The growth of the microorganisms in the medium was examined after a 24-h incubation. The inhibitory effect of each compound on the growth of the microorganisms was calculated from the optical density measured at 595 nm, turbidity, and size of the inhibition zone around the treated paper disc. The minimum inhiitory concentration (MIC) of compounds 4 to 7 against S. aureus was 0.08, 0.05, 1.3 and 0.02 ${\mu}M$, respectively, and 0.09, 0.1, 0.2 and 100 ${\mu}M$ against C. albicans. The $IC_{50}$ (50% inhibition) values of compounds 5 and 6 were 3.1 and 6.4 ${\mu}M$ against S. aureus, respectively, and 10 and 2.4 ${\mu}M$ against C. albicans. Therefore, compounds 4 to 6 were the most potent anti-microbial agents among the eight compounds tested.

• Advances in Energy Research
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• v.1 no.2
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• pp.97-106
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• 2013

This study designs and tests a photovoltaic system with distributed maximum power point tracking (DMPPT) methodology using a field programmable gate array (FPGA) controller. Each solar panel in the distributed PV system is equipped with a newly designed DC/DC converter and the panel's voltage output is regulated by a FPGA controller using PI control. Power from each solar panel on the system is optimized by another controller where the quadratic maximization MPPT algorithm is used to ensure the panel's output power is always maximized. Experiments are carried out at atmospheric insolation with partial shading conditions using 4 amorphous silicon thin film solar panels of 2 different grades fabricated by Chi-Mei Energy. It is found that distributed MPPT requires only 100ms to find the maximum power point of the system. Compared with the traditional centralized PV (CPV) system, the distributed PV (DPV) system harvests more than 4% of solar energy in atmospheric weather condition, and 22% in average under 19% partial shading of one solar panel in the system. Test results for a 1.84 kW rated system composed by 8 poly-Si PV panels using another DC/DC converter design also confirm that the proposed system can be easily implemented into a larger PV power system. Additionally, the use of NI sbRIO-9642 FPGA-based controller is capable of controlling over 16 sets of PV modules, and a number of controllers can cooperate via the network if needed.

• Korean Journal of Microbiology
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• v.40 no.1
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• pp.60-64
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• 2004

We tested gentamicin - resistant bacteria isolated from hospital sewage to confirm the presence of aac(3)II encoding aminoglycoside- (3)-N- acetyltransferase by dot-blot hybridization. A probe from the internal fragment of aac(3)II was hybridized to DNA from 41 % (39/95) of gentamicin resistant isolates. PCR was performed with primers from aac(3)II and Tn3. Of 39 strains, 13 strains had Tn3-aac(3)II structure. Minimal inhibitory concentration (MIC) test demonstrated that 18 strains containing Tn3-aac(3)II showed higher resistance to gentamicin than those of other strains. Thirteen strains were identified as 5 Escherichia coli, 3 Acinetobacter johnsonii, 2 Enterobacter agglomerans, 2 Micrococcus luteus, and 1 Pseudomonas facilis. These results suggest that gentamicin-resistant determinant of Tn3-aac(3)II structure was widely distributed in the gentamicin-resistant bacteria.

• Natural Product Sciences
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• v.26 no.4
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• pp.317-325
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• 2020

A new dimer stilbene [Monalittorin (1)] and ten known compounds [engeletin (2), aurantiamide acetate (3), lupeol (4), friedelin (5), quercetin (6), tiliroside (7), rutoside (8), astragalin (9), isoquercitrin (10) and quercimeritroside (11)] have been isolated from the leaves of Monanthotaxis littoralis (Annonaceae). The structures of these compounds were established by interpretation of their data, mainly, HR-TOFESIMS, 1-D NMR (1H and 13C) and 2-D NMR (1H-1H COSY, HSQC, HMBC and NOESY) and by comparison with the literature. The evaluation of their antimicrobial activities against three bacteria (Staphylococcus aureus ATCC 25923, Escherichia coli S2 (1) and Pseudomonas aeruginosa PA01) and three fungal strains (Candida albicans ATCC10231, Candida tropicalis PK233 and Cryptococcus neoformans H99) using broth micro dilution method, showed the largest antimicrobial activities of EtOAc fraction and compounds 1, 5, 6, 8 and 11 (MIC = 8 - 64 ㎍/mL). In addition, EtOAc fraction presented synergistic effect with Vancomycin and fluconazole against the tested microorganisms.

• Journal of Veterinary Science
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• v.21 no.2
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• pp.32.1-32.13
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• 2020

Levofloxacin pharmacokinetic profiles were evaluated in 6 healthy female rabbits after intravenous (I/V), intramuscular (I/M), or subcutaneous (S/C) administration routes at a single dose of 5 mg/kg in a 3 × 3 cross-over study. Plasma levofloxacin concentrations were detected using a validated Ultra Performance Liquid Chromatography method with a fluorescence detector. Levofloxacin was quantifiable up to 10 h post-drug administration. Mean AUC_0-last values of 9.03 ± 2.66, 9.07 ± 1.80, and 9.28 ± 1.56 mg/h^*L were obtained via I/V, I/M, and S/C, respectively. Plasma clearance was 0.6 mL/g*h after I/V administration. Peak plasma concentrations using the I/M and S/C routes were 3.33 ± 0.39 and 2.91 ± 0.56 ㎍/mL. Bioavailability values, after extravascular administration were complete, - 105% ± 27% (I/M) and 118% ± 40% (S/C). Average extraction ratio of levofloxacin after I/V administration was 7%. Additionally, levofloxacin administration effects on tear production and osmolarity were evaluated. Tear osmolarity decreased within 48 h post-drug administration. All 3 levofloxacin administration routes produced similar pharmacokinetic profiles. The studied dose is unlikely to be effective in rabbits; however, it was calculated that a daily dose of 29 mg/kg appears effective for I/V administration for pathogens with MIC < 0.5 ㎍/mL.

• Journal of Ginseng Research
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• v.48 no.2
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• pp.236-244
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• 2024

Background: Fusarium oxysporum (F. oxysporum) is the primary pathogenic fungus that causes Panax notoginseng (P. notoginseng) root rot disease. To control the disease, safe and efficient antifungal pesticides must currently be developed. Methods: In this study, we prepared and characterized a nanoemulsion of Foeniculum vulgare essential oil (Ne-FvEO) using ultrasonic technology and evaluated its stability. Traditional Foeniculum vulgare essential oil (T-FvEO) was prepared simultaneously with 1/1000 Tween-80 and 20/1000 dimethyl sulfoxide (DMSO). The effects and inhibitory mechanism of Ne-FvEO and T-FvEO in F. oxysporum were investigated through combined transcriptome and metabolome analyses. Results: Results showed that the minimum inhibitory concentration (MIC) of Ne-FvEO decreased from 3.65 mg/mL to 0.35 mg/mL, and its bioavailability increased by 10-fold. The results of gas chromatography/mass spectrometry (GC/MS) showed that T-FvEO did not contain a high content of estragole compared to Foeniculum vulgare essential oil (FvEO) and Ne-FvEO. Combined metabolome and transcriptome analysis showed that both emulsions inhibited the growth and development of F. oxysporum through the synthesis of the cell wall and cell membrane, energy metabolism, and genetic information of F. oxysporum mycelium. Ne-FvEO also inhibited the expression of 2-oxoglutarate dehydrogenase and isocitrate dehydrogenase and reduced the content of 2-oxoglutarate, which inhibited the germination of spores. Conclusion: Our findings suggest that Ne-FvEO effectively inhibited the growth of F. oxysporum in P. notoginseng in vivo. The findings contribute to our comprehension of the antifungal mechanism of essential oils (EOs) and lay the groundwork for the creation of plant-derived antifungal medicines.