• 한국미생물·생명공학회지
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• 제49권2호
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• pp.131-137
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• 2021

This study aimed at isolating lactic acid bacteria with anti-MRSA (methicillin-resistant Staphylococcus aureus) bacteriocin activity from fermented shrimp. We selected three strains, named Weissella sp. S1, S2, and S3, using analysis based on 16S rRNA gene sequences. All strains showed appropriate growth in an MRS medium containing 5% (w/v) NaCl and showed antibacterial activities against Bacillus cereus, Escherichia coli, Staphylococcus aureus, and MRSA. The strains exhibited similar growth rates at 0-5% NaCl, with approximate reduction in growth rate observed at 9% NaCl. Weissella sp. S1, S2, and S3 exhibited maximum growth rates at pH 7, 9, and 8, respectively. The crude bacteriocin was prepared from Weissella sp. S3 and subjected to characterization. The remaining activities after 30 min of exposure at each temperature were 100%, beyond 75%, and 49% at 4℃ and 37℃, 50℃ and 70℃, and 100℃, respectively. The remaining activities after 24 h of exposure at each pH were 100%, 75%, and 49% at pH 3 and 5, 7 and 9, and 10, respectively. Use of 50% (v/v) ethanol or isopropanol treatment did not diminish the antibacterial activity of the bacteriocin, while the 50% (v/v) hexane treatment reduced the activity by 51%. The molecular weight of the bacteriocin was nearly 6 kDa that was quantified using tricine-SDS-PAGE. Our findings suggest that Weissella sp. S3 may be considered a probiotic and useful source of antimicrobial substances in the development of bio-preservatives for food or in MRSA treatment.

• 동의생리병리학회지
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• 제23권3호
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• pp.704-709
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• 2009

The emergence of methicillin-resistant of Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE) has led to an urgent need for the discovery and development of new antibacterial agents. As part of an ongoing investigation into the antibacterial properties of the natural products, (2S)-7,4'-dihydroxy-5-methoxy-8-(${\gamma}$, ${\gamma}$-dimethylally)-f1avanone (2S-DMDF), isolated from the roots of Sophora flavescens, was found to be antibacterial active MRSA and VRE. Sophora flavescens has been used as antibacterial, antiviral, antiprotozoal, anti-inflammatory. Therefore, this study investigated the antibacterial activity of 2S-DMDF against all the bacterial strains tested. In this result, at the end point of an optically clear well, the minimum inhibitory concentrations (MICs) ranged from 0.97 to 15.6 mg/ml for 2S-DMDF, from 125 to 256 mg/ml for ampicillin, and from 64 to 512 mg/ml for gentamicin with MRSA, also, 7.8 to 15.6 mg/ml for 2S-DMDF, from 125 to 256 mg/ml for ampicillin, and from 512 to 1024< mg/ml for vacomicin with VRE. These findings indicated that the application of the tested 2S-DMDF alone might prove useful in the control and treatment of MRSA and VRE infections.

• 생명과학회지
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• 제21권4호
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• pp.589-595
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• 2011

질병를 유발하는 미생물들의 항생물질에 대한 증가하는 내성문제를 극복할 수 있는 새로운 항생물질을 개발하고자 항생물질을 생산하는 방선균을 탐색하여 특성화하는데 본 연구는 초점을 맞추고 있다. 충청북도 일대의 토양으로부터 PDA, starch casein agar 등의 배지를 이용하여 100여 개의 방선균주를 순수분리하였다. 순수분리된 방선균주 중 메티실린 내성 황색포도상구균에 가장 활성이 뛰어난 BCNU 1030을 선발하여 형태학적, 생화학적, 분자생물학적 방법으로 동정한 결과 Streptomyces 속으로 동정되었다. 분리균주인 BCNU 1030은 MRSA를 포함한 그람양성 및 그람음성세균에 대한 폭넓은 항균스펙트럼을 가졌다. BCNU 1030의 디클로로메탄 추출물은 MRSA CCARM 3090에 대하여 최소$0.78\;{\mu}g/ml$의 농도에서 저해활성이 있음이 확인되었다. 그러므로 BCNU 1030은 새로운 anti-MRSA 항생물질의 개발에 있어서 가능성을 가지고 있는 것으로 판단된다.

• Korean Chemical Engineering Research
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• 제56권2호
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• pp.245-251
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• 2018

본 연구에서는 커피(Coffea arabica)의 에탄올 추출물을 이용하여 기능성 화장품소재로서의 가능성을 검토하였다. 미백활성으로는 tyrosinase 저해 활성과 멜라닌 함량을 측정하였으며, 항산화 활성으로는 SOD-like activity를 측정하였고, 그 결과 $500{\mu}g/mL$의 농도에서 $94.8{\pm}6.2%$의 활성을 나타내었다. CAE는 3개의 그람양성균과 6개의 그람음성균을 대상으로 항균활성을 조사하였으며, 그 결과 그람음성균에 대해서는 폭넓은 활성을 나타내었지만, 그람양성균에 대한 활성은 나타내지 않았다. 하지만 항생제내성균주인 MRSA CCARM3561에는 강한 활성을 나타내었다. 반면에 Candida albicanse에 대한 항곰팡이 활성은 나타내지 않았다. Tyrosinase 저해활성과 DOPA 산화능은 대조군인 arbutin 보다는 낮게 나타내었고, B16-F10 melanoma cell에 대한 멜라닌 생합성 저해능은 농도 의존적으로 감소하는 경향을 보였으며, $100{\mu}g/mL$의 농도에서 89.2%를 나타내었다. 이러한 결과들은 커피 추출물이 천연물, 무독성 항균제 또한 천연 화장품 소재로써의 가치가 있음을 나타내는 것이다.

• Journal of Microbiology and Biotechnology
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• 제32권2호
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• pp.220-227
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• 2022

The spread of antibiotic-resistant strains of Staphylococcus aureus, a gram-positive opportunistic pathogen, has increased due to the frequent use of antibiotics. Inhibition of the quorum-sensing systems of biofilm-producing strains using plant extracts represents an efficient approach for controlling infections. Torilis japonica is a medicinal herb showing various bioactivities; however, no studies have reported the anti-biofilm effects of T. japonica extracts against drug-resistant S. aureus. In this study, we evaluated the inhibitory effects of T. japonica ethanol extract (TJE) on biofilm production in methicillin-sensitive S. aureus (MSSA) KCTC 1927, methicillin-resistant S. aureus (MRSA) KCCM 40510, and MRSA KCCM 40511. Biofilm assays showed that TJE could inhibit biofilm formation in all strains. Furthermore, the hemolysis of sheep blood was found to be reduced when the strains were treated with TJE. The mRNA expression of agrA, sarA, icaA, hla, and RNAIII was evaluated using reverse transcription-polymerase chain reaction to determine the effect of TJE on the regulation of genes encoding quorum sensing-related virulence factors in MSSA and MRSA. The expression of hla reduced in a concentration-dependent manner upon treatment with TJE. Moreover, the expression levels of other genes were significantly reduced compared to those in the control group. In conclusion, TJE can suppress biofilm formation and virulence factor-related gene expression in MSSA and MRSA strains. The extract may therefore be used to develop treatments for infections caused by antibiotic-resistant S. aureus.

• 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.

• 생명과학회지
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• 제29권1호
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• pp.84-89
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• 2019

신규 항세균물질을 탐색하는 사전조사에서 몇몇 분리균주들이 그람양성 세균과 그람음성 세균 모두에 항균활성을 보이며, 심지어 methicillin내성 Staphylococcus aureus (MRSA)에도 항균활성을 나타내었다. 이들 균주 중에서 한 균주가 표현형과 계통분석을 이용하여 특히 16S 리보좀 RNA 유전자 염기서열에 기초하여 Pseudomonas aeruginosa로 동정되었다. BCNU 1204 균주의 항균물질은 King's medium B (pH 7.0)에서 $35^{\circ}C$의 온도 조건으로 4일 배양 후 가장 최대로 생산되었다. 항균물질을 각종 유기용매로 분획한 결과, P. aeruginosa BCNU 1204의 dichloromethane (DCM)분획과 ethylacetate (EA) 분획이 그람 양성 세균에 강력한 항균활성을 보였으며, 특히 ethylacetate (EA) 분획이 methicillin내성 Staphylococcus aureus (MRSA)에 대하여 강한 항균활성을 나타내었다. Recycling preparative LC와 preparative TLC 로 활성물질 하나(분획 5-2)를 분리하여 GC-MS 분석한 결과 phenazine 화합물에 속하는 phenazine-1-carboxylic acid 로 동정하였다. 그리고 MRSA 균주에 대한 최소저해농도(minimum inhibitory concentration, MIC)가 MRSA균주인 CCARM 3089, 3090, 3091 그리고 3095 균주에 대하여 각각 $25{\mu}g/ml$, $50{\mu}g/ml$, ${\geq}25{\mu}g/ml$ 그리고 ${\geq}50{\mu}g/ml$ 임을 확인하였다. 그러므로 P. aeruginosa BCNU 1204 분리균주는 항 MRSA 항생물질을 개발하기 위한 잠재 가치가 높은 생물자원으로 기대되며, P. aeruginosa BCNU 1204 균주로부터 리더 화합물을 획득하기 위한 보다 많은 연구가 요구된다.

• 생약학회지
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• 제54권2호
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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.

• 대한약학회:학술대회논문집
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• 대한약학회 2001년도 Proceedings of International Convention of the Pharmaceutical Society of Korea
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• pp.235.3-236
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• 2001

• Bulletin of the Korean Chemical Society
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• 제35권9호
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• pp.2818-2824
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• 2014

Trp residue is considered as one of the important constituents in antimicrobial peptides (AMPs) as it presence secured good activities in many cases. However, it is preferable to be changed because of their sensitivity towards light. We have synthesized the short Trp-rich AMP Pac-525 and its analogues to investigate the possibility of His(chx) as possible replacement analogue for Trp in AMPs. Based on the assay result of the antibacterial activity including anti-MRSA activity, His(chx) is considered as good candidate for the Trp replacement. Through these study, we found that His(chx) had several merits to design therapeutic antimicrobial agents compare to Trp in terms of i) increasing antibacterial activity without hemolytic activity, ii) successful in designing the short peptide (only four residues), iii) having anti-MRSA activity, iv) overcoming the light sensitivity. Furthermore, transmission electron microscopy (TEM) and dye leakage experiments suggested that P11 and P16 containing His(chx) kill bacteria via forming pore/ion channels on bacterial cell membranes.