• 생약학회지
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• 제53권2호
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• pp.87-95
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• 2022

Methicillin resistance Staphylococcus aureus (MRSA) is a gram-positive bacterium, the most commonly isolated bacterial human pathogen. JiYu-san is one of the natural products used to treat diseases in the folk recipe. In this study, we investigated the antimicrobial activity of EtOH 70% extracts of JiYu-san (JYS) against MRSA. The antibacterial activity of JYS against MRSA strain was evaluated using minimum inhibitory concentration (MIC), checkerboard dilution test, and time-kill assay. The effect of JYS on the immune mechanism of MRSA was confirmed through cell membrane permeability tests and energy metabolism tests, and the antibacterial activity mechanism was performed using qRT-PCR and western blot. As a result, in the antibacterial test of JYS, the MIC was measured to be 1.9~1000 ㎍/mL, and synergistic or showed a partial synergistic effect. In addition, JYS showed antibacterial activity in a combination test with DCCD or TX-100. In a study on the mechanism of action of antibacterial activity, it was found that JYS suppressed MRSA resistance genes and proteins. These results suggest that JYS has antibacterial activity and provides great potential as a natural antibiotic by modulating the immune mechanism against MRSA.

• 대한수의학회지
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• 제51권4호
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• pp.267-275
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• 2011

Methicillin-resistant Staphylococcus (S.) aureus (MRSA) is one of the most important nosocomial pathogens worldwide and the emergence of this strain has become a major clinical problem. In this study, we investigated the prevalence of MRSA and their genetic characteristics in 69 S. aureus isolated from humans and animals. In human isolates, higher antimicrobial resistance rates were observed against penicillin (80.6%), followed by erythromycin (11.9%) and tetracycline (9.0%). All of them were susceptible to clindamycin, enrofloxacin, novobiocin, pirlimycin, trimethoprim/sulfamethoxazole and vancomycin. The resistance patterns in animal isolates were similar to those of human isolates. Two (2.9%) MRSA strains were isolated from human (n = 1) and animal (n = 1), and these isolates were confirmed as carrying the mecA gene. One isolate originating from human was resistant to 7 drugs and the other isolate derived from animal was resistant to 11 drugs. Staphylococcal cassette chromosome mec (SCCmec) variant IIIB was identified in animal isolate but SCCmec type of an isolate from human was not exactly determined. Two MRSA isolates showed unrelated PFGE pattern between them. Our results indicated although the frequency of MRSA isolates from humans and animals was low, a continuous surveillance and monitoring should be called for to prevent the contamination and spread of MRSA in the community. To our knowledge, this is the first time that SCCmec type variant IIIB was detected from animals in Korea.

• Archives of Plastic Surgery
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• 제33권5호
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• pp.632-636
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• 2006

Purpose: Methicillin-Resistant-Staphylococcus aureus(MRSA) has been increasingly recognized as a cause of nosocomial infection. MRSA is hardly-controllable organism among the pathogen of nosocomial infection, because it is resistant to most antibiotics except vancomycin, and local treatment with most antiseptics are not effective to eradicate MRSA from the infection. The effectiveness of Vacuum-Assisted-Closure(VAC) was reported widely. we tried to modify original VAC. We tried VAC dressing on MRSA infected wound to evaluate whether or not the VAC is effective to eradicate MRSA which existed in the open wound. Methods: From September 2003 to December 2003, 24 patients admitted to the plastic and reconstructive surgery and orthopedic surgery, were studied. All patients were found to be positive in previous wound. Using clinical randomized study, 24 patients were divided into two groups: VAC dressing group and the $Betadine^{(R)}$ dressing group(control). During treatment, wound culture was done twice a week for evaluation of MRSA infection elimination. Results: The mean period that MRSA become not detected in all case was 17.1 days in VAC dressing group, and 25.8 days in control group, respectively. The p value was 0.013. The result reveals that the VAC dressing group is more effective to MRSA infection control. As a result, the VAC dressing was more effective in MRSA infected wound than conventional dressing. Conclusion: Through this study, we found objective result of VAC dressing. We hope that VAC dressing is more widely applied to fresh and infected wound.

• 한국약용작물학회지
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• 제22권6호
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• pp.504-509
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• 2014

Methicillin-resistant Staphylococcus aureus (MRSA) is a substantial contributor to morbidity and mortality. In search of a natural products capable of inhibiting this multidrug resistant bacteria, we have investigated the antimicrobial activity of brazilein (BRZ) isolated from Caesalpinia sappan L. (Leguminosae) against 8 different strains of Staphylococcus aureus (S. aureus). New antimicrobial activity was found using the minimum inhibitory concentrations (MICs), broth dilution as well as checkerboard method. Against the 8 strains, the minimum inhibitory concentrations of BRZ were in the range of $62.5-500{\mu}g/mL$. From those results we performed the checkerboard test to determine the synergism of BRZ in combination with Hygromycin-b (HgB) against 4 strains. The combined activity of BRZ and HgB against 4 strains resulted in a fractional inhibitory concentrations index (FICI) ranging from 0.18-0.5. The effect of BRZ with HgB was found to be synergistic. We found that BRZ reduced the MICs of HgB. BRZ and HgB could lead to the development of new combination antibiotics against MRSA infection.

• 대한의생명과학회지
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• 제11권4호
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• pp.447-453
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• 2005

A total of 108 strains of MRSA (Methicillin-resistant Staphylococcus aureus) clinical isolates was collected from $121^{st}$ general hospital (U.S. military hospital), Korean healthcare facility from January to March in 2005 and Wonju Christian hospital in 1999. Antimicrobial susceptibility test by Vitek System and MIC test using oxacillin and cephalothin stripes by E-test were executed. PCR based detection of mecA gene was performed on the all of MRSA clinical isolates, too. MRSA clinical isolates were characterized with antimicrobial resistance patterns, PCR based detection of mecA gene and validation of the multiplex PCR strategy of SCCmec among clinical isolates.

• Journal of Chest Surgery
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• 제48권6호
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• pp.443-446
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• 2015

A 36-year-old man, who had undergone thoracoscopic anterior spinal fusion using the plate system and posterior screw fusion three months previously, presented to our hospital with left flank pain and fever. Computed tomography indicated the presence of a psoas muscle abscess. However, after two days of percutaneous catheter drainage, a mycotic abdominal aortic pseudoaneurysm was detected via computed tomography. We performed in situ revascularization using a prosthetic graft with omental wrapping. Methicillin-resistant Staphylococcus aureus was identified on blood and pus culture, and systemic vancomycin was administered for one month. Although the abscess recurred, it was successfully treated with percutaneous catheter drainage and systemic vancomycin administration for three months, without the need for instrumentation removal. The patient remained asymptomatic throughout two years of follow-up.

• 복식문화연구
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• 제11권3호
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• pp.441-446
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• 2003

Water-insoluble chitosan with molecular weight of 2,000,000, 500,000, 80,000, and 40,000 and more than 90% of degree of deacetylation were used to test antibacterial activity of chitosan against a pathogenic bacteria, methicillin resistant Staphylococcus aureus(MRSA), which is being issued in the world. As experimental method, Agar plate Smear Method and Agar plate Contact Method were used. The moleculur weight of chitosan didn't exert significant influences on its antibacterial activity against MRSA but chitosan having molecular weight 40,000, 80,000 and 150,000 showed the excellent antibacterial activity. The antibacterial efHciency was excellent in applying it after chitosan was dissolved in acetic acid solution, while the antibacterial efficiency was not expressed nearly in case of applying after chitosan was dissolved in neutral water. Therefore, it is considered that chitosan can show the antibacterial efficiency only if a positive ion status of -NH₃/sup +/ is maintained. MIC of chitosan/acetic acid solution and cotton fabrics finished with chitosan/acetic acid solution showed in concentration of 0.05%.

• 한국의류산업학회지
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• 제4권6호
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• pp.557-563
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• 2002

Water-soluble chitosan and water-insoluble chitosan with molecular weight of 2,000,000, 500,000, 80,000, and 40,000 with more than 90%of degree of deacetylation were produced to test antibacterial activity of chitosan against a pathogenic bacteria, Methicillin Resistant Staphylococcus aureus(MRSA). the AATCC Test Method 100and Modified AATCC Test Method 100 were used to evaluate the antibacterial activity of chitosan. Antibacterial activity of chitosan/acetic acid solution was the same when they were tested by two different methods, but those of polyester fabrics treated with chitosan/acetic acid solution were different in different antibacterial test. So several problems were found in the experimental methods. The AATCC Test Method 100 seems that excessive nutrition exists in inoculum solution by quantitative analysis on the basis the result of antibacterial activity on chitosan/acetic acid solution and amount of chitosan attached to the surface of treated fabrics.

• Fisheries and Aquatic Sciences
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• 제3권3_4호
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• pp.217-221
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• 2000

In previous study, marine actinomycetes producing the antibiotics were investigated to invent new antibiotics from east coast of Korea. The optimum growth conditions of Streptomyces sp. NS 13239 were $28^{\circ}C$, pH 7.0 and $3\%$ of NaCl concentration in various media. Streptomyces sp. NS 13239 showed strong antimicrobial activity against gram-positive bacteria, specially Methicillin resistant Staphylococcus aureus (MRSA), but just weak antimicrobial activity against yeasts and mold. On the other hand, it did not show antimicrobial activity against gram-negative bacteria. The optimum conditions for producing antibiotics were almost consistent with optimum growth conditions except carbon source and nitrogen source.

• Journal of Microbiology and Biotechnology
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• 제9권5호
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• pp.572-575
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• 1999

Miconazole was estimated to have a minimum inhibitory concentration of 0.78 ㎍/㎖ against the methicillin-resistant strains of Staphylococcus aureus (MRSA). The antibacterial activity of miconazole against MRSA was bacteriostatic in cation-adjusted Mueller-Hinton broth, but bacteriocidal in saline solution. The anti-MRSA activity of miconazole did not show a significant change under the susceptibility-testing conditions such as various inoculum sizes, pHs, or cations (Ca/sup ++/ or Mg/sup ++/) which was added to the medium. However, the anti-MRSA activity of miconazole was completely suppressed by lipophilic a-tocopherol (50 ㎍/㎖), but definitely not by water-soluble ascorbic acid.