• 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.

• Journal of Microbiology
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• 제45권1호
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• pp.6-10
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• 2007

Culture broth of a streptomycete isolate, Streptomyces sp. CS684 showed antibacterial activity on methicilin resistant Staphylococcus aureus (MRSA) and vancomycin resistant enterococci (VRE). Among purified substances from the organism, CSU-1, which is active against MRSA and VRE, is a $C_{37}H_{62}O_{12}Na\;(M^+,721.3875)$, and identified as laidlomycin. The anti-MRSA and anti-VRE activity of CSU-1 was stronger than oxacillin and vancomycin. Phylogenetic analysis showed that strain CS684 is very similar to Streptomyces ardus NRRL $2817^T$, whereas the ability of Streptomyces sp. CS684 to produce laidlomycin was shown to be unique.

• 한국자원식물학회지
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• 제31권6호
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• pp.719-724
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• 2018

Methicillin-resistant Staphylococcus aureus (MRSA) is a bacterium responsible for a number of infections in humans that are difficult to treat, and as a result, is a substantial contributor to morbidity and mortality. In the present study, in search of natural products capable of inhibiting this multidrug-resistant bacterium, we investigated the antimicrobial activity of Lysimachia clethroides Duby root. The antibacterial activities of EtOH extract of Lysimachia clethroides Duby root and its n-hexane, EtOAc, n-BuOH and water fractions were evaluated against 15 strains of methicillin-resistant staphylococcus aureus (MRSA) and 1 standard methicillin-susceptible S. aureus (MSSA) strain by using the minimal inhibitory concentrations (MICs) assay, colorimetric assay using MTT test, checkerboard dilution test. Antimicrobial activity of n-hexane fraction of Lysimachia clethroides Duby root was remarkable. Against the 16 strains, the minimum inhibitory concentrations (MICs) were in the range of $31.25-62.5{\mu}g/ml$ and FICI values for n-hexane fraction of Lysimachia clethroides Duby root+AM and n-hexane fraction of Lysimachia clethroides Duby root+OX were checkerboard method performed using the MRSA, MSSA and one clinical isolate strains via MICI 0.12-1 and 0.25-0.75, showing the increase of synergistic effect. When combined together, these antibiotic effects were dramatically increased. These effective combinations could be new promising agents in the management of MRSA.

• 미생물학회지
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• 제44권4호
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• pp.326-332
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• 2008

국내 토양으로부터 MRSA에 대해 항균활성을 보이는 세균들을 분리하였다. 이들 가운데 가장 높은 항MRSA 균 활성을 보인 YK5 균주는 호기성 간균으로 운동성이 있고, 내생포자를 형성하였으며, 인돌을 형성하지 않았고, mannitol을 분해하여 산을 생성시키지 않았다. 이 균주의 16S rRNA 유전자 염기서열은 Paenibacillus 속 세균들의 유전자와 $95{\sim}98%$의 상동성을 나타냈는데 특히 P. elgii와 가장 높은 상동성을 보였으나, 기타 생리 생화학적 특성에서 다른 점들이 관찰되어 P. incheonensis YK5로 명명되었다. P. incheonensis YK5 를 SST 배지에 접종하여 $37^{\circ}C$에서 96 시간 배양한 다음 그 상등액으로 부터 부탄올로 추출된 항균물질은 그람 양성균인 MRSA 20 균주들과 Streptococcus pneumoniae, 그람 음성균인 Pseudomonas aeruginosa 10균주들, Salmonella spp., Shigella spp., Escherichia coli와 Klebsiella pneumoniae 및 인체병원성 진균인 Cryptococcus neoformans와 Trichophyton spp.에 대하여 광범위한 항균효과를 나타냈다. 또한 이 항균물질은 $20{\sim}100^{\circ}C$ 사이의 온도구간에서 안정한 활성을 유지하였을 뿐만 아니라, pH $3.0{\sim}7.0$의 넓은 pH범위에서 활성을 나타내 MRSA를 비롯한 다양한 병원균에 대한 항생물질로서의 가능성을 보였다.

• 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%.

• 한국환경과학회지
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• 제33권3호
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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.

• 동의생리병리학회지
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• 제26권6호
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• pp.886-893
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• 2012

Methicillin-Resistant Staphylococcus aureus (MRSA) is a cephalosporin and beta-lactam antibiotic-resistant strain. In most cases, MRSA is spread from infected patients and infection rates are growing increasingly. Furthermore, increased resistance to antibiotics is causing serious problems in the world. Staphylococcus aureus is responsible for both nosocomial and community-based infections that range from relatively minor skin and soft tissue infections to life-threatening systemic infections. Therefore, there is a need to develop alternative antimicrobial drugs for the treatment of infectious diseases. In this study, we investigated antimicrobial activity of oriental medicine prescription against MRSA. The minimum inhibitory concentration (MIC) of Sohamhyung-tang water extract against S. aureus strains ranged from 500 to 2,000 ${\mu}g/mL$, so we have it confirmed that a strong antibacterial effect. Also, the combinations of Sohamhyung-tang water extract and conventional antibiotics exhibited improved inhibition of MRSA with synergy effect. We suggest that Sohamhyung-tang water extract against MRSA have antibacterial activity, it has potential as alternatives to antibiotic agent. We suggest that the Sohamhyung-tang 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.

• International Journal of Oral Biology
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• 제38권2호
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• pp.51-54
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• 2013

Methicillin-resistant Staphylococcus aureus (MRSA) is one of the important causative microbes for nosocomial infection and has been isolated from the dental environment. The purpose of this study was to investigate the antimicrobial activity of linalool and ${\alpha}$-terpineol against MRSA isolates from a Korean population. In the experiments, we determined the minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) of these two compounds against 18 strains of MRSA. The data revealed that the $MIC_{90}/MBC_{90}$ values of linalool and ${\alpha}$-terpineol against MRSA were >12.8 mg/ml and 6.4 mg/ml, respectively. These results indicate that ${\alpha}$-terpineol has more potent antimicrobial activity against MRSA than linalool and may have utility as an anti-MRSA cleansing agent for dental instruments and dental unit chairs.

• Natural Product Sciences
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• 제20권1호
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• pp.39-43
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• 2014

Papenfussiella kuromo (PK) is a marine plant and an abundant ecological resource for the future; it is found in almost 80% of the terrestrial biosphere. The aim of this study was to investigate the antibacterial activity of PK against methicillin-resistant Staphylococcus aureus (MRSA), multidrug-resistant pathogen. The minimum inhibitory concentrations (MICs) of PK hexane fraction (PKH) against 7 strains of MRSA ranged from 1.0 to 2.0 mg/mL. In the checkerboard dilution method, a synergistic effect of the PKH and the antibiotics (oxacillin and norfloxacin) was seen. PKH markedly reduced the MIC of each of the 4 antibiotics against MRSA. The time-kill assay showed that the synergistic activity of PKH and an antibiotic reduced the bacterial counts below the lowest detectable limit after 24 h. These findings suggest that PKH has antibacterial activity, and may be important baseline data in future extensive studies of living marine resources as a source of compounds active against MRSA.

• International Journal of Industrial Entomology and Biomaterials
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• 제14권2호
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• pp.137-142
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• 2007

The antibacterial activity of Korean honey bee venom (KBV) was examined against seven major bacterial mastitis pathogens, Enterococcus faecium, Escherichia coli, Methicillin resistant Staphylococcus aureus (MRSA), Staphylococcus aureus, Streptococcus intermedius, Streptococcus oralis and Streptococcus uberis isolated from infected mammary quarters of cows. Seven bacterial mastitis pathogens were studied for antibacterial activity of the KBV by disc diffusion assay, minimal inhibitory concentrations (MIC) and bacterial count in milk samples. The KBV showed activity against Ent. faecium, E. coli, MRSA, Staph. aureus, Strep. intermedius. The order of susceptibility of the bacteria against the KBV was Staph. aureus>MRSA>E. coli>Strep. intermedius>Ent. faecium>Strep. oralis>Strep. uberis. The MIC against Staph. aureus, MRSA and E. coli were stronger effect as compared with standard drug. The effect of the KBV ($100{\mu}g\;ml^{-1}$) on the viability of Ent. faecium, E. coli, MRSA, Staph. aureus, Strep. intermedius, Strep. oralis and Strep. uberis in milk differed significantly with each other within 12 h incubation period. The results indicate that KBV has significant antibacterial effects against major bacterial mastitis bacteria, Ent. faecium, E.coli, MRSA, Staph. aureus, Strep. intermedius. Results of the study indicate the potential use of KBV as alternative to antibiotic therapy. Further investigations are needed though to confirm its efficacy and its effects on the animals.