• Fisheries and Aquatic Sciences
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• 제11권1호
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• pp.1-6
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• 2008

In an effort to discover an alternative therapeutic agent against methicillin-resistant Staphylococcus aureus (MRSA), several medicinal plants and seaweeds were evaluated for its antibacterial activity against MRSA. A methanolic extract of the Phaeophyta Ecklonia stolonifera exhibited significant antibacterial activity against MRSA. To perform more detailed investigation on antibacterial activity, the methanol extract of E. stolonifera was further fractionated with organic solvents such as hexane, dimethylchloride, ethyl acetate, and n-butanol. Among them, the hexane fraction showed the strongest antibacterial activity against MRSA strains with MIC from 500 to $600 {\mu}g/mL$. The fraction also exhibited a bactericidal activity against MRSA, indicating that E. stolonifera contains a bactericidal substance against MRSA.

• 미생물학회지
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• 제42권1호
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• pp.54-58
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• 2006

항생제 내성균에 대처 할 수 있는 새로운 항생제의 개발에는 많은 시간과 인력 및 개발비가마 필요하며 새로운 항생제들이 생산되어도 균들은 빠르면 수개월내에 내성을 획득한다. 이 문제의 해결방법의 하나로 전통적으로 감염질환의 치료에 사용되어온 백작약 추출물의 methicillin-resistant Staphylococcus aureus(MRSA)에 대한 항균활성 보유여부를 조사한 결과 백작약의 dichloromethane 추출물이 MRSA에 대하여 높은 항균활성을 나타내어 앞으로 새로운 항균재로서의 개발 및 사용 가능성이 있을 것으로 판단된다.

• 대한의생명과학회지
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• 제16권4호
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• pp.331-339
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• 2010

This study aims to evaluate the effect of Photodynamic Therapy (PDT) against methicillin-resistant Staphylococcus aureus with high-level mupirocin resistance (Hi-Mup MRSA). To examine the antimicrobial effect of photogem-mediated PDT against Hi-Mup MRSA, CFU quantifications, bacteria cell viability tests, and disk diffusion antimicrobial susceptibility tests were evaluated. In addition, one of PDT mechanisms was investigated by accumulating photogem ($10\;{\mu}g/ml$) in Hi-Mup MRSA. Photogem-mediated PDT properly inhibited the colony formation of Hi-Mup MRSA. Viable bacteria decreased greatly after a PDT application with photogem $10\;{\mu}g/ml$ at energy density $15\;J/cm^2$. The diameter of the inhibition zone around susceptible disks increased after PDT. In addition, we confirmed the accumulation of photogem in bacteria through fluorescent images. These results demonstrated that excellent photosensitization of Hi-Mup MRSA can be achieved using photogem with 630 nm LED irradiation. Thus, PDT may make survival Hi-Mup MRSA inactive.

• 한국미생물·생명공학회지
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• 제51권2호
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• pp.212-213
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• 2023

Once known as a major community-genotype, sequence type (ST) 72 methicillin-resistant Staphylococcus aureus (MRSA) strains have been increasingly identified in hospital-associated infections in Korea. Here, we report the complete genome sequence of SA520 isolated from a patient in Korea.

• 대한의생명과학회지
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• 제30권1호
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• pp.32-35
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• 2024

In vitro antimicrobial activities of hot water extracts of Chamaecyparis obtuse, for methicillin-resistant Staphylococcus aureus (MRSA) was compared to commonly used conventional antimicrobial agents. All MRSA was susceptible to linezolid or vancomycin, but also to erythromycin. MIC range and MIC₉₀ to erythromycin, clindamycin, levofloxacin, tetracycline for MRSA were each 4 ㎍/mL, 2 ~ >128 ㎍/mL, ≤0.06 ~ >128 ㎍/mL, 0.25 ~ >128 ㎍/mL, 0.25~64 ㎍/mL and 4 ㎍/mL, .128 ㎍/mL, >128 ㎍/mL, >128 ㎍/mL, 64 ㎍/mL. The hot water extracts of leaf of C. obtuse had the lowest MIC range, MIC₅₀, and MIC₉₀ (0.125 µL/mL) for the MRSA tested, and it was possible more potent than various conventional antimicrobial agents. Screen antibacterial drug candidate with high antibacterial activity such as derivatives of C. obtuse leaf extract such as terpinen-4-ol or using combined therapy with commercialized antibacterial agents will likely be helpful in treating refractory MRSA infections.

• 보건의료생명과학 논문지
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• 제9권2호
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• pp.303-308
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• 2021

최근 MRSA와 같은 항생제 내성 균주에 감염되는 사례가 점점 증가하는 추세이며, 특히 원내에서 감염되는 경우도 상당수 찾아볼 수 있다. 본 연구에서는 강원에 소재한 대학에 재학생들을 대상으로 병원 실습 경험 여부를 조사하고, 각각 비강 검체를 채취하여 황색포도알균인 Staphylococcus aureus 균주 및 MRSA (methicillin resistant Staphylococcus aureus)의 존재 여부를 동정하여 임상 실습 경험이 있는 학생과 MRSA 검출에 대한 관계를 확인하고자 하였다. 실험에 참여한 인원은 64명 학생으로 남학생 22명, 여학생 42명이다. 멸균된 면봉으로 비강 검체를 채취하여 수송 배지인 Thioglycollate broth로 수송한 뒤, 선택배지인 MSA(mannitol salt agar)에 접종했다. 균을 배양하여 다양한 생화학적 test 및 상용화 키트인 API Kit를 사용하여 분리 및 동정을 하였고, 최종으로 분자생물학적 방법을 사용하여 MRSA 검출 양상을 확인하였다. 64명 학생 중 Staphylococcus aureus 균주가 46명에서 검출되었으며, 46명의 검체 중에 22명에서 MRSA가 검출되었다, 22명의 학생 중에 남학생은 5명, 여학생은 17명이었으며, 15명의 학생은 최근 1년 이내에 입원, 수술력 또는 임상현장실습 등의 의료기관 관련 MRSA(HR-MRSA)로 확인되었고, 나머지 7명(%)은 CA-MRSA로 확인되었다. MRSA가 검출된 학생들의 감염경로를 확인한 결과, 평상시 의료기관 방문 여부와 임상 실습경험 등으로 비추어 볼 때 원내에서 감염되었다고 추정할 수 있으며, 임상실습에 참가하는 학생들을 대상으로 원내 감염 예방을 위한 추가적인 교육과 학생들의 적극적인 참여가 필요하다고 여겨진다.

• 한국동물위생학회지
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• 제33권3호
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• pp.233-240
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• 2010

Methicillin-resistant coagulase-negative staphylococci (MRCNS) were isolated from the respiratory sites of chickens in 4 farms and slaughter house located in Chungnam provinces. Isolation of coagulase-negative staphylococci (CNS) was positive for 61 (26.6%) of the 229 chickens tested, and isolation of MRCNS was positive for 17 (27.9%) of the isolated CNS. A total of 17 MRCNS isolates were selected and subjected to identification. Of the 17 MRCNS isolates selected, 6 were identified as Staphylococcus cohnii, 2 as S. saprophyticus, 3 as S. simulans, 3 as S. lentus, 2 as S. carnosus, and 1 as S. xylosus. The MRCNS isolates were resistant to many beta-lactam antibiotics, and some isolates were also resistant to macrolide and aminoglycoside antibiotics. The mecA gene was detected in some isolates of each MRCNS strains. The mecA-positive isolates were classified into five staphylococcal cassette chromosome mec (SCCmec). SCCmec types I to IV were detected in isolates from chickens.

• 한국동물위생학회지
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• 제41권4호
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• pp.229-237
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• 2018

Identification of antibiotic resistant bacteria isolated from animals is necessary for seeking a proper treatment and for preventing the spread of the bacteria among animals. Methicillin-resistant Staphylococcus pseudintermedius (MRSP) is of worldwide concern in veterinary medicine. This study was conducted to investigate the antimicrobial susceptibility of Staphylococcus pseudintermedius (S. pseudintermedius) isolated from dogs and cats. Out of the total number of 150 specimens, 35 isolates (23.3％) were identified as S. pseudintermedius when tested by MALDI-TOF MS (Matrix Assisted Laser Desorption Ionization-Time of Flight Mass Spectroscopy). Among them, 5 isolates (14.3%) were the case of MRSP. In the results of the antimicrobial susceptibility test, the isolates of S. pseudintermedius were susceptible to amikacin (100%), cephalothin (100%), vancomycin (100%), amoxicillin (85.7%), oxacillin (85.7%), enrofloxacin (82.8%), chloramphenicol (80%). On the other hand, they were resistant to penicillin (71.4%), tetracycline (48.6%), ampicillin (37.1%), kanamycin (31.5%), erythromycin (31.4%), respectively.

• Journal of Microbiology and Biotechnology
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• 제31권9호
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• pp.1288-1294
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• 2021

There are a growing number of reports of hospital-acquired infections caused by pathogenic bacteria, especially methicillin-resistant Staphylococcus aureus (MRSA). Many plant products are now being used as a natural means of exploring antimicrobial agents against different types of human pathogenic bacteria. In this research, we sought to isolate and identify an active molecule from Sedum takesimense that has possible antibacterial activity against various clinical isolates of MRSA. NMR analysis revealed that the structure of the HPLC-purified compound was 1,2,4,6-tetra-O-galloyl-glucose. The minimum inhibitory concentration (MIC) of different extract fractions against numerous pathogenic bacteria was determined, and the actively purified compound has potent antibacterial activity against multidrug-resistant pathogenic bacteria, i.e., MRSA and its clinical isolates. In addition, the combination of the active compound and β-lactam antibiotics (e.g., oxacillin) demonstrated synergistic action against MRSA, with a fractional inhibitory concentration (FIC) index of 0.281. The current research revealed an alternative approach to combating pathogenesis caused by multi-drug resistant bacteria using plant materials. Furthermore, using a combination approach in which the active plant-derived compound is combined with antibiotics has proved to be a successful way of destroying pathogens synergistically.

• 대한의생명과학회지
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• 제14권4호
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• pp.269-274
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• 2008

Methicillin-resistant Staphylococcus aureus (MRSA) is one of the most common nosocomial pathogens. It is associated with hospitals is now being isolated in the community. The aim of this study was to evaluate the antibacterial effect of photodynamic therapy using Photogem and 630 nm LED on MRSA and methicillin-sensitive Staphylococcus aureus (MSSA). The broth cultured MRSA and MSSA incubated with various concentrations of Photogem (500,50,5 and $0.5{\mu}g/mL$) for 4 h. Then 630 nm LED was given at $9\;J/cm^2$, $20{\mu}l$ of the exposed bacteria solution was inoculated onto agar plate. Plates were incubated for 24 hand colonies were counted. The PDT group was effective in killing MRSA and MSSA at the Photogem dose of $50{\mu}g/mL$. But MSSA is more sensitive than MRSA in photodynamic effect. Other groups (light only, sensitizer only, or no treatment) observed no bacterial cell killing. These results raise the possibility of using PDT with or without antimicrobial drugs to eradicate MRSA and MSSA. In order to confirm this result, we need to further study bacterial death mechanism and in vivo study.