• Korean Journal of Pharmacognosy
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• v.54 no.2
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• pp.72-79
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• 2023

MRSA is Staphylococcus aureus resistant to β-lactam antibiotics, and is a worldwide infectious disease. Even with the discovery of new antibiotics, resistance develops rapidly, so new alternatives are needed. Jakyakgamcho-tang (JGT) is a combination of Jakyak and Gamcho, and has been mainly used as an antispasmodic and analgesic in oriental medicine. This study was conducted to find out whether there is an effect on MRSA in relation to the anti-inflammatory effect of JGT and the antibacterial effect of Jakyak and Gamcho found in previous studies. In this study, in order to investigate the antibacterial activity of JGT and the combined effect of existing antibiotics, after extracting JGT with 70% EtoH, the disc diffusion method, minimum inhibitory concentration (MIC), drug combination effect (FICI), and time-kill analysis (Time-kill assay), metabolic inhibition, Western blot and qRT-PCR analysis were used to confirm the antibacterial activity mechanism of MRSA of JGT. As a result of the experiment, all of MRSA showed antibacterial activity in JGT's disc diffusion method, and the MIC was 250-1000 ㎍/mL. When existing antibiotics and JGT were combined with drugs, most had synergy or partial synergy. In addition, it was confirmed that the degree of bacterial growth was suppressed over time when simultaneous administration for 24 hours. JGT showed a synergistic effect when administered together with the ATPase-inhibitor DCCD, suggesting that it affected the inhibition of ATPase. As a result of observing the expression of PBP2a, and hla protein in the JGT-treated group and the untreated control group through wstern blot, it was confirmed that the protein expression of the JGT-treated group was significantly suppressed, and the expression levels of mecA, mecR1 and hla genes were also suppressed during JGT treatment. was observed by qRT-PCR. Combining the results of the experiment, it can be seen that JGT has antibacterial activity in MRSA, and when combined with existing antibiotics, the effect was increased compared to treatment with the drug alone. This suggests that JGT can be an alternative to treatment for antibiotic resistance of MRSA.

• Korean Journal of Agricultural Science
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• v.10 no.2
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• pp.193-199
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• 1983

The authors carried out bovine mastitis test by California Mastitis test (CMT) for the milk from dairy cows in the suburbs of Daejeon. Among the CMT positive milk, Staphylococcus aureus were isolated and, for the proper selection of the commercial antibacterial agents, the strains were tested for the resistant test to the agents. The results obtained were summarized as follows. 1. The resistant test appeared graduate resistance is in such cases continuously repeat with the therapeutic antibacterial agents. 2. The result of resistant test appeared the weakly resistance, untill 4 times subculture in the Rifamastene, Neo-cillin, and 6 times in the Abimasten-100, Neo-masti, Special formular and mastalone. 3. In Tardomycel-L there was rare resistant reactions, untill 6 times subculture. 4. The author recommend that select the antibacterial agents by resistant test and use the selective agents in turn.

• Proceedings of the Korean Society of Sericultural Science Conference
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• 2002.10a
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• pp.118-118
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• 2002

No Abstract, See Full Text

• Korean Journal of Veterinary Research
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• v.50 no.4
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• pp.279-284
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• 2010

Combination therapy of antibiotics is leading to improved efficacy or safety profiles with decrease emergence of bacterial resistance. Because of this benefit, many of antibacterial combinations have been used in veterinary practice for the past few decades. The purpose of this study was to examine the in vitro activity of an amoxicillin alone and in combination with other antibiotics against pathogenic bacteria of fish origin. Based on the fractional inhibitory concentration (FIC) index (FIC $$\leq_-$$ 0.5), a synergistic interaction was shown in combination of florfenicol with amoxicillin or cefuroxime. The combination of florfenicol and amoxillin showed higher antibacterial activity than that of florfenicol and cefuroxime. Ratio of amoxicillin and florfenicol in combination was 1 : 1, which showed the antibacterial activity against bacterial isolates of fish as compared with other ratios. A synergetic effect of the combination (amoxicillin and florfenicol) was further confirmed in the time-kill curve study. The study showed a better in vitro antibacterial activity of a 1 : 1 combination of amoxicillin and florfenicol than the individual antibacterial against bacterial isolates of fish. In conclusion, the combination of florfenicol and amoxicillin may serve as a potential antibacterial therapy in fishes infected pathogenic bacteria.

• Korean Journal of Pharmacognosy
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• v.41 no.1
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• pp.38-42
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• 2010

Curcumin content of butanol fraction from C. longa was found to be 22.4942% of the highest content. However, in DPPH radical scavenging ability and antibacterial activity against methicillin resistance Staphylococcus aureus(MRSA, CCARM3696), ethylacetate fraction contained 2.5791% of curcumin was exhibited highest activity. In comparison of enhancing antibiotic(ampicillin) effect against MRSA, ethanol extract contained 1.7838% of curcumin showed more strong activity. This indicates that the ethanol extract and some fractions from C. longa can have antibacterial activity and enhancing antibiotic effect possibly without curcumin. Appropriate use of antimicrobial agent was important point prior to the development of new antibiotics. And in that sence, extract and fractions of C. longa were worth using as synergist of antibiotics and natural antimicrobial agent.

• Journal of Environmental Science International
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• v.33 no.3
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• pp.205-215
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• 2024

Antibiotics are substances produced by microorganisms that kill or inhibit and are essential for infectious diseases management. This study aimed to provide basic data for overcoming antibiotic resistance in the marine bacterium LJ-18. The API 20NE and API 50CH kits were used to identify this microorganism. Morphological, physiological, and biochemical properties were investigated using MacFaddin's manuals. Subsequently, isolated LJ-18 was found to belong to a genus of Streptomyces that forms mycelia. LJ-18 also grew well at 28-32℃ on modified Bennett's agar. To isolate and purify the antibacterial compound, LJ-18 culture was divided into ethyl acetate and distilled water fractions. Considerable antimicrobial activity against various pathogenic microorganisms, including methicillin-resistant Staphylococcus aureus (MRSA), was confirmed in the C₁₈ ODS open column fractions. Peak 2 compound was obtained using reversed-phase HPLC. As a result, this compound had a significant antimicrobial activity against various pathogenic microorganisms. In particular, it showed strong activity against MRSA, Mycobacterium smegmatis, Bacillus subtilis, Bacillus cereus, and Staphylococcus aureus.

• The Journal of Internal Korean Medicine
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• v.34 no.3
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• pp.278-288
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• 2013

Objectives : Methicillin-resistant Staphylococcus aureus (MRSA) has a cephalosporin and beta-lactam antibiotic-resistant strains. MRSA is one of the major pathogens causing hospital infection and the isolation ratio of MRSA has gradually increased. Consequently, increased resistance to antibiotics is causing serious problems in the world. Therefore, there is a need to develop alternative antimicrobial drugs for the treatment of infectious diseases. Methods : The antibacterial activities of Ipyo-san were evaluated against 2 strains of MRSA and 1 standard Methicillin-susceptible staphylococcus aureus (MSSA) strain by using the disc diffusion method, minimal inhibitory concentrations (MIC) assay, colorimetric assay using MTT test, checkerboard dilution test and time-kill assay performed under dark. Results : The MIC of Ipyo-san water extract against S. aureus strains ranged from 1000 to $2,000{\mu}g/ml$, so we confirmed that it had a strong antibacterial effect. Also, the combinations of Ipyo-san water extract and conventional antibiotics exhibited improved inhibition of MRSA with synergy effect. We suggest that Ipyo-san water extract against MRSA has antibacterial activity so it has potential as alternatives to antibiotic agents. For the combination test, we used Triton X-100 (TX) and DCCD for measurement of membrane permeability and inhibitor of ATPase. As a result, antimicrobial activity of Ipyo-san water extract was affected by the cell membrane. Conclusions : We suggest that the Ipyo-san water extract lead the treatment of bacterial infection to solve the resistance and remaining side-effect problems that are the major weak points of traditional antibiotics.

• Microbiology and Biotechnology Letters
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• v.35 no.1
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• pp.41-44
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• 2007

This study was carried out to investigate the effects of wood vinegar on growth and resistance of peppers. It was observed that heights and dried weights of the peppers treated with diluted wood vinegar were increased, especially 1:500 diluted wood vinegar was the most effective. The Wood vinegar also showed antibacterial activity against Xanthomonas axonopodis pv. vesicatoria directly. The growth of X. axonopodis pv. vesicatoria was completely inhibited when incubated for 12 hours at $30^{\circ}C$ with non diluted wood vinegar. The peppers applied wood vinegar did not show induced systemic resistance after injecting X. axonopodis pv. vesicatoria.

• Corrosion Science and Technology
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• v.23 no.1
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• pp.72-81
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• 2024

The Ti-6Al-4V alloy is widely used as an implant material due to its higher fatigue strength and strengthto-weight ratio compared to pure titanium, excellent corrosion resistance, and bone-like properties that promote osseointegration. For rapid osseointegration, the adhesion between the titanium surface and cellular biomolecules is crucial because adhesion, morphology, function, and proliferation are influenced by surface characteristics. Polymeric peptides and similar coating technologies have limited effectiveness, prompting a demand for alternative materials. There is growing interest in 2D nanomaterials, such as MoS₂, for good corrosion resistance and antibacterial, and bioactive properties. However, to coat MoS₂ thin films onto titanium, typically a low-temperature hydrothermal synthesis method is required, resulting in the synthesis of films with a toxic 1T@2H crystalline structure. In this study, through high-temperature annealing, we transformed them into a non-toxic 2H structure. The implant coating technique proposed in this study has good corrosion resistance and biocompatibility, and antibacterial properties.

• Journal of Microbiology and Biotechnology
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• v.19 no.2
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• pp.178-186
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• 2009

To examine their potential as probiotics, acid and bile tolerance, antibiotics resistance, adhesion capacity to Caco-2 and HT-29, and antibacterial activity, of LAB isolated from Korean fermented foods such. as dongchimi, kimchi, Meju, and doenjang were assayed against foodborne pathogenic bacteria. DC 55, DC 136, DC 222, KC 21, KC 24, KC 34, KC 43, KC 117, MJ 54, MJ 301, SP 33, and SP 170 strains were resistant to acid and bile conditions. In particular, DC 55, DC 136, KC 24, KC 43, and MJ 301 strains were highly resistant to higher than 20 ${\mu}g/ml$ concentrations of vancomycin, streptomycin sulfate, or amoxicillin, whereas, DC 222, KC 21, KC 34, KC 117, MJ 54, and SP 33 strains were susceptible to lower than 2 ${\mu}g/ml$ concentrations of those antibiotics. The adhesion to HT-29 and Caco-2 cells varied with the strains tested in a strain-dependent manner. The highest level of adhesion was observed with DC 55, KC 21, KC 24, and MJ 301 strains, having higher than 50% of adhesion to HT-29 or Caco-2 cells. In addition, Staphylococcus aureus was the most sensitive to KC 21, showing an inhibition of about 70%, and the antibacterial activity of KC 21 against S. aureus resulted most likely from both organic acids and bacteriocin. Based on its phenotypic characteristics and utilization of various sugars, the KC 21 strain was identified as Lactobacillus plantarum.