• Natural Product Sciences
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• v.24 no.4
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• pp.225-228
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• 2018

By activity-guided fractionation, gliotoxin was isolated as an antibacterial metabolite of the fungus Penicillium decumbens which was derived from the jellyfish Nemopilema nomurai. Gliotoxin was further evaluated for antibacterial activity against several piscine and human MDR (multidrug resistance) pathogens. Gliotoxin showed significant antibacterial activity against Gram-positive piscine pathogens such as Streptococcus iniae FP5228, Streptococcus iniae FP3187, Streptococcus parauberis FP3287, Streptococcus parauberis SPOF3K, S. parauberis KSP28, and Lactococcus garvieae FP5245. Gliotoxin showed strong activity especially against S. parauberis SPOF3K and S. iniae FP5228, which are resistant to oxytetracycline. It is noteworthy that gliotoxin effectively suppressed streptococci which are the major pathogens for piscine infection and mortality in aquaculture industry. Gliotoxin also showed strong antibacterial activity against multidrug- resistant human pathogens (MDR) including Enterococcus faecium 5270 and MRSA (methicillin-resistant Staphylococcus aureus) 3089.

• Journal of Chest Surgery
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• v.43 no.4
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• pp.381-386
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• 2010

Background: Sternal wound infection (SWI) is an important complication after cardiac surgery. The aim of this study was to investigate the predictors affecting sternal wound infection and preventive factors including short term Vancomycin therapy in patients who underwent coronary artery bypass grafting (CABG). Material and Method: A retrospective study was done using data collected from January 2001 through December 2007. This included 219 patients who had isolated CABG. The definition of SWI was documentation from a microbiological study and a requirement for simple closure or other surgical revision. Result: The overall incidence of SWI was 7.8% (n=17). The causative organisms were methicillin resistant Staphylococcus aureus (MRSA, n=13), methicillin resistant Staphylococcus epidermidis (n=2), Pseudomonas aeruginosa (n=1), and Candida albicans (n=1). Ten cases had deep sternal wound infection with mediastinitis; 7 cases had a superficial wound infection. Infection-related mortality was low (1/17; 6%). Diabetes mellitus (p=0.006) and smoking history (p=0.020) were factors that predicted high risk. Short term use of vancomycin decreased the incidence of MRSA-associated SWI (p=0.009). For treatment, curettage and rewiring or flap were needed in most cases (88%, n=14). Conclusion: Patients who had diabetes mellitus and a smoking history need careful management. Short term use of vancomycin is effective for prevention of SWI with MRSA.

• Pediatric Infection and Vaccine
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• v.5 no.2
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• pp.276-282
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• 1998

Staphylococcal pneumonia caused by staphylococcus aureus can be characterized by its severity and rapid progress as a bacterial infection. The disease shows a high mortality in younger patients, especially in infants unless early and appropriate treatment is carried out. Treatment can be made of medical method alone but in cases of surgical interventions are needed, immediate surgical methods such as closed or open drainage of pleural fluid, lobectomy and decortication should be followed with combination of medical therapy. The choice of antibiotic should be made by proper antibiotic sensitivities tests. For a methicillin sensitive S. areus(MSSA), the penicillase resistant penicillin would be the first choice and for a methicillin resistant S. aureus (MRSA), the glycopeptides such as vancomycin would be the first one. Other drugs can also be used if the bacterial agents show any sensitivities to these drugs. Commonly, the chest roentgenographic findings reveal infiltrations, empyema, pneumothorax, pleural effusion, atelectasis or pneumatoceles in staphylococcal pneumonia and this fact easily can lead the physicians to its diagnosis as soon as possible. We experienced 5 cases of staphylococcal pneumonia in infants, proven by through bacterial cultures and report them with brief review of the related literatures.

• Journal of Life Science
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• v.27 no.4
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• pp.476-481
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• 2017

Polyphenols are secondary metabolites produced by higher plants and have been used as antiallergic, anticancer, antihypertensive, antiinflammatory, antimicrobial and antioxidant agents. They are generally divided into flavonoids and non-flavonoids. The antimicrobial activity of flavonoids are stronger than that of non-flavonoids. The skeleton structures of flavonoids possessing antimicrobial activity are chalcone, flavan-3-ol (catechin), flavanone, flavone, flavonol and proanthocyanidin. The flavonols are shown antibacterial activity against several gram-positive bacteria (Actinomyces naeslundii, Lactobacillus acidophilus and Staphylococcus aureus) and gram-negative bacteria (Fusobacterium nucleatum, Porphyromonas gingivalis, Prevotella melaninogenica and Prevotella oralis). Among of non-flavonoids, caffeic acids, ferulic acids and gallic acids showed antimicrobial activity against gram-positive (Listeria monocytogenes and S. aureus) and gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa). These are found to be more efficient against the E. coli, L. monocytogenes, P. aeruginosa and S. aureus than antibiotics such as gentamicin and streptomycin. The kaempferol and quercetin showed synergistic effect with ciprofloxacin and rifampicin against S. aureus and methicillin resistant S. aureus (MRSA). Epigallocatechin gallate (EGCG) acts synergistically with various ${\beta}-lactam$ antibiotics against MRSA. In particular, the epicatechin, epigallocatechin (EGC), EGCG and gallocatechin gallate from Korean green tea has antibacterial activity against MRSA clinical isolates and the combination of tea polyphenols and oxacillin was synergistic for all the clinical MRSA isolates.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.12
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• pp.503-511
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• 2017

This study was conducted to evaluate the anti-inflammatory activity and clinical efficacy of a sample (A.C.C. extracts) obtained by distillation extraction of 14 herbal medicines including Phellodendron bark. To confirm this, the amount of nitric oxide (NO) produced by the cells in RAW 264.7 cells stimulated by lipopolysaccharide (LPS) and the changes in the production of inflammatory cytokines such as tumor necrosis factor (TNF)-${\alpha}$, interleukin(IL)-$1{\beta}$ and IL-6 were determined. The results showed that A.C.C. extracts strongly inhibited the production of NO and inflammatory cytokines increased by LPS without cytotoxicity. In addition, A.C.C. extracts showed strong bacterial reduction rates of 99.9% in Pseudomonas aeruginosa, Staphylococcus aureus, MRSA (Methicillin-resistant Staphylococcus aureus), Candida albicans and Streptococcus mutans. These findings indicate that A.C.C. extracts are effective ingredients with a strong antimicrobial effect together with an anti-inflammatory effect. In addition, when A.C.C. extracts were applied to infants and toddlers who were suffering from diaper rash, itching, and perspiration symptoms, symptoms of rash, atopy, rash, itching, and heat rash were improved. After the lapse of time, it was visually confirmed that it was considerably relaxed. These findings confirm that A.C.C. extracts comprise a clinically effective anti-inflammatory and anti-bacterial agent that alleviates symptoms such as diaper rash and fever and may therefore be an effective alternative to inflammatory diseases.

• Korean Journal of Medicinal Crop Science
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• v.19 no.4
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• pp.238-245
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• 2011

In this study, we investigated antioxidative activity, antibacterial activity against pathogenic strains including methicillin resistant Staphylococcus aureus (MRSA), and tyrosinase inhibitory activity in 75% ethanol extract of Taraxacum coreanum and its fractions. The total polyphenol and flavonoid contents of the extract were 238.59mg/g and 33.18mg/g and the total polyphenol and flavonoid contents of the ethyl acetate fraction were 427.81mg/g and 148.90mg/g as the highest content of fractions. In DPPH radical scavenging ability, $SC_{50}$ values of the ethyl acetate and butanol fraction were 38.40${\mu}g/ml$ and 82.28 ${\mu}g/ml$, respectively. In antibacterial activity by the disc diffusion assay against S. aureus, S. epidermidis and MRSA, the ethyl acetate fraction showed stronger antibacterial activity than other fractions and the extract. Especially, the ethyl acetate fraction was exhibited effective antibacterial activity against MRSA. In the cytotoxicity measurement by MTT assay, the extract and fractions were exhibited Raw 264.7 cell viabilities of 96.32~143.21% as nontoxic result in concentration of 5~100 ${\mu}g/ml$. As a result, the ethyl acetate fraction of the 75% ethanol extract from T. coreanum could be applicable to functional materials for related fields.

• Korean Journal of Poultry Science
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• v.49 no.2
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• pp.69-77
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• 2022

Antimicrobial peptides (AMPs) play an important role in innate immunity against pathogenic infections. AMPs exterminate pathogenic bacteria by disrupting cell membranes or inhibiting intracellular molecules. NK-2, first identified in pigs and derived from NK-lysin, has antimicrobial effects against bacteria and parasites. In this study, chimeric peptides (cpNK) of chicken and pig NK-2 and cpNK-derived peptides (cpNK-a1 and cpNK-a2) were synthesized, and their antimicrobial effects against various pathogenic bacteria such as Escherichia coli, Salmonella spp., Listeria monocytogenes, Staphylococcus aureus, and methicillin-resistant Staphylococcus aureus (MRSA) were investigated. The structure of chimeric peptides from chicken and pig NK-2, cpNK, include α-helix like NK-2 and peptide net charge was +9 like porcine NK-2. The cpNK peptide showed powerful bactericidal effects against most bacterial species, including MRSA, especially against gram-negative bacteria. Furthermore, cpNK-derived short peptides, cpNK-a1 and a2 also showed bactericidal activity, but the effects were weaker than those of cpNK. Therefore, we conclude that cpNK- and cpNK-derived short peptides have the potential to be used as antibiotic alternatives.

• Journal of Life Science
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• v.20 no.12
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• pp.1792-1800
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• 2010

In this study, we isolated five macrolactin compounds from a fermentation broth of Bacillus polyfermenticus KJS-2. The macrolactin compounds were structurally identified as macrolactin A (MA), 7-O-malonyl macrolactin A (MMA), 7-O-succinyl macrolactin A (SMA), macrolactin E (ME) and macrolactin F (MF) via a variety of NMR techniques, COZY, DEPT, HMQC and HMBC, and mass and specific rotation assays. The three macrolactin compounds, MA, MMA and SMA, profoundly inhibited the growth of both vancomycin-resistant Enterococci (VREs) and methicillin-resistant Staphylococcus aureus (MRSA), the inhibition of which were estimated via a disc agar diffusion bioassay. MA, MMA, and SMA exhibited antibacterial activities superior to those of vancomycin and teicoplanin.

• Microbiology and Biotechnology Letters
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• v.49 no.2
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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.

• Fisheries and Aquatic Sciences
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• v.16 no.4
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• pp.229-235
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• 2013

In an effort to develop biopolymer-based antioxidant and antibacterial materials, a chitosan-phloroglucinol conjugate was prepared and cellular antioxidant activity and minimum inhibitory concentration against foodborne pathogens and methicillin-resistant Staphylococcus aureus (MRSA) evaluated. The chitosan-phloroglucinol conjugate showed higher antioxidant activities than the unmodified chitosan (P < 0.05). The chitosan-phloroglucinol conjugate showed 62.29% reactive oxygen species scavenging activity, 56.11% lipid peroxidation inhibition activity, and 2.21-fold increase of glutathione expression in mouse macrophage cells. Additionally, the chitosan-phloroglucinol conjugate exhibited higher antibacterial activities than the unmodified chitosan, and the chitosan-phloroglucinol conjugate showed fourfold higher antibacterial activities against MRSA and clinical isolates and twofold higher activities against foodborne pathogens compared to the unmodified chitosan.