• Korean Journal of Fisheries and Aquatic Sciences
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• v.54 no.4
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• pp.552-560
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• 2021

This study investigated anti-inflammatory and antibacterial activities of Sedum takesimense ethanolic extract, and 3 isolated compounds. To confirm anti-inflammatory and anti-acne activities, a nitric oxide (NO) inhibition assay, pro-inflammatory factor (TNF-α, IL-1β, and IL-8) inhibition assays, and minimum inhibitory concentration (MIC) tests were performed. The 3 isolated compounds were identified as 4,6-di-O-galloylarbutin (OGA), 2,4,6-tri-O-galloyl-glucose (OGG), and 1,2,4,6-tetra-O-galloyl-β-glucose (TOGG). The ethanolic extract and isolated compounds (OGA, OGG, TOGG) effectively inhibited production of NO and pro-inflammatory cytokines (TNF-α, IL-1β, and IL-8). Furthermore, OGG and TOGG exhibited MIC values toward Cutibacterium acnes of 12.5 ㎍/mL and 3.2 ㎍/mL, respectively. These results suggest that S. takesimense extract exerts an anti-inflammatory effect on LPS-induced RAW264.7 cells, and an antibacterial efficacy against C. acnes.

• Journal of the FoodService Safety
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• v.1 no.1
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• pp.27-35
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• 2020

Salt is a common seasoning agent used in various processed foods, especially in kimchi and salted seafood (jeotgal). This study was conducted to investigate the efficacy of salt with antimicrobial substances (acetic acid, garlic extract, carvacrol, nisin, thymol, and their combination (acetic acid+nisin+thymol)) on improvement of antibacterial effects of salt against foodborne pathogens. Salt (10%) was prepared using six different types of 0.2% natural antimicrobial substances. The antibacterial effect of salt combined with natural antimicrobial substances was evaluated against foodborne pathogens using the broth micro-dilution method and growth curve plotted using absorbance measurements. For the five foodborne pathogens, the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of salt without antimicrobial substances as control were in the range of 24~>50,000 ㎍/mL and >50,000 ㎍/mL, respectively. Salt with nisin, thymol, or garlic extract showed strong inhibitory effects and their MIC against L. monocytogenes were 49, 12,500, and 24 ㎍/mL, respectively. In particular, salt with nisin showed inhibitory activities against Gram-positive bacteria. However, all the antimicrobial substances were less effective against Gram-negative bacteria such as E. coli O157:H7 and S. Typhimurium than Gram-positive bacteria. These results could be used for the development of salt with natural antimicrobial substances especially targeted against L. monocytogenes. This would enable the lowering of saline concentration while improving the storability of food.

• Journal of Microbiology and Biotechnology
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• v.32 no.9
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• pp.1195-1208
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• 2022

Silver nanoparticles (AgNPs) have potential applications in medicine, photocatalysis, agriculture, and cosmetic fields due to their unique physicochemical properties and strong antimicrobial activity. Here, AgNPs were synthesized using actinobacterial SL19 strain, isolated from acidic forest soil in Poland, and confirmed by UV-vis and FTIR spectroscopy, TEM, and zeta potential analysis. The AgNPs were polydispersed, stable, spherical, and small, with an average size of 23 nm. The FTIR study revealed the presence of bonds characteristic of proteins that cover nanoparticles. These proteins were then studied by using liquid chromatography with tandem mass spectrometry (LC-MS/MS) and identified with the highest similarity to hypothetical protein and porin with molecular masses equal to 41 and 38 kDa, respectively. Our AgNPs exhibited remarkable antibacterial activity against Escherichia coli and Pseudomonas aeruginosa. The combined, synergistic action of these synthesized AgNPs with commercial antibiotics (ampicillin, kanamycin, streptomycin, and tetracycline) enabled dose reductions in both components and increased their antimicrobial efficacy, especially in the case of streptomycin and tetracycline. Furthermore, the in vitro activity of the AgNPs on human cancer cell lines (MCF-7, A375, A549, and HepG2) showed cancer-specific sensitivity, while the genotoxic activity was evaluated by Ames assay, which revealed a lack of mutagenicity on the part of nanoparticles in Salmonella Typhimurium TA98 strain. We also studied the impact of the AgNPs on the catalytic and photocatalytic degradation of methyl orange (MO). The decomposition of MO was observed by a decrease in intensity of absorbance within time. The results of our study proved the easy, fast, and efficient synthesis of AgNPs using acidophilic actinomycete SL19 strain and demonstrated the remarkable potential of these AgNPs as anticancer and antibacterial agents. However, the properties and activity of such particles can vary by biosynthesized batch.

• Journal of Veterinary Science
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• v.25 no.1
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• pp.12.1-12.10
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• 2024

Background: Staphylococcus aureus and S. pseudintermedius are the major etiological agents of staphylococcal infections in humans, livestock, and companion animals. The misuse of antimicrobial drugs has led to the emergence of antimicrobial-resistant Staphylococcus spp., including methicillin-resistant S. aureus (MRSA) and methicillin-resistant S. pseudintermedius (MRSP). One novel therapeutic approach against MRSA and MRSP is a peptide nucleic acid (PNA) that can bind to the target nucleotide strands and block expression. Previously, two PNAs conjugated with cell-penetrating peptides (P-PNAs), antisense PNA (ASP)-cmk and ASP-deoD, targeting two essential genes in S. aureus, were constructed, and their antibacterial activities were analyzed. Objectives: This study analyzed the combined antibacterial effects of P-PNAs on S. aureus and S. pseudintermedius clinical isolates. Methods: S. aureus ATCC 29740 cells were treated simultaneously with serially diluted ASP-cmk and ASP-deoD, and the minimal inhibitory concentrations (MICs) were measured. The combined P-PNA mixture was then treated with S. aureus and S. pseudintermedius veterinary isolates at the determined MIC, and the antibacterial effect was examined. Results: The combined treatment of two P-PNAs showed higher antibacterial activity than the individual treatments. The MICs of two individual P-PNAs were 20 and 25 µM, whereas that of the combined treatment was 10 µM. The application of a combined treatment to clinical Staphylococcus spp. revealed S. aureus isolates to be resistant to P-PNAs and S. pseudintermedius isolates to be susceptible. Conclusions: These observations highlight the complexity of designing ASPs with high efficacy for potential applications in treating staphylococcal infections in humans and animals.

• ALGAE
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• v.29 no.1
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• pp.47-55
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• 2014

To develop effective and safe acne vulgaris therapies with a continuing demand for new solutions, we investigated unique efficacy of an antibacterial agent from marine brown alga Eisenia bicyclis in treating acne vulgaris. The methanolic extract of E. bicyclis exhibited potential antibacterial activity against acne-related bacteria. The ethyl acetate fraction showed the strongest antibacterial activity against the bacteria among solvent fractions. Six compounds (1-6), previously isolated from the ethyl acetate fraction of E. bicyclis, were evaluated for antibacterial activity against acne-related bacteria. Among them, compound 2 (fucofuroeckol-A [FF]) exhibited the highest antibacterial activity against acne-related bacteria with a minimum inhibitory concentration (MIC) ranging from 32 to $128{\mu}g\;mL^{-1}$. Furthermore, FF clearly reversed the high-level erythromycin and lincomycin resistance of Propionibacterium acnes. The MIC values of erythromycin against P. acnes were dramatically reduced from 2,048 to $1.0{\mu}g\;mL^{-1}$ in combination with MIC of FF ($64{\mu}g\;mL^{-1}$). The fractional inhibitory concentration indices of erythromycin and lincomycin were measured from 0.500 to 0.751 in combination with 32 or $64{\mu}g\;mL^{-1}$ of FF against all tested P. acnes strains, suggesting that FF-erythromycin and FF-lincomycin combinations exert a weak synergistic effect against P. acnes. The results of this study suggest that the compounds derived from E. bicyclis can be a potential source of natural antibacterial agents and a pharmaceutical component against acnerelated bacteria.

• Archives of Plastic Surgery
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• v.37 no.2
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• pp.115-121
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• 2010

Purpose: Many topical agents had been used for contaminated wound treatment. Although antimicrobial ointments were widely used as topical agents, their comparative antibacterial and wound healing effects were largely unreported. The purpose of this study was to compare antibacterial effects and wound healing effects of common topical ointments on infected full thickness skin defect in the mouse. Methods: One full thickness skin defects in the mice (n=60) were developed on the back and left open for twenty-four hours. Sixty mice were divided into four groups: group B (dressing with Bactroban$^{(R)}$, n=15), group I (dressing with Iodosorb$^{(R)}$, n=15), group T (dressing with Terramycin$^{(R)}$, n=15), group G (control group, dressing with dry gauze, n=15). The size of wound defects and the grades of wound healing were evaluated at 4, 7, 10 days, and antibacterial effect was evaluated with restricted zone in Mueller Hinton agar by disk diffusion method. After the wound was left open for twenty-four hours, many Staphylococcus aureus was cultured. The wound defect size was decreased in order of Bactroban$^{(R)}$ (B), Iodosorb$^{(R)}$ (I), Terramycin$^{(R)}$ and gauze dressing group in all days, but difference among experimental groups was not statistically significant. The grade score of wound healing was increased in order of Bactroban$^{(R)}$, Iodosorb$^{(R)}$, Terramycin$^{(R)}$ and gauze dressing group, and the difference was statistically significant. Antibacterial effect for was increased in order of Bactroban$^{(R)}$, Iodosorb$^{(R)}$, Terramycin$^{(R)}$ and gauze dressing group, and the difference was statistically significant. Conclusion: Topical antimicrobial ointments application was effective against wound infections by S. aureus. Bactroban$^{(R)}$ may be an optimal topical treatment for infected wounds according to this study. However, further study is necessary to evaluate the clinical efficacy of antimicrobial ointments and to search for the mechanisms that explain their effects.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.48 no.6
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• pp.904-912
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• 2015

There is a great deal of research interest regarding substitutes for antibiotics because of various obstacles to the efficacy and use of antibiotics. We isolated and analyzed diversity of microbiota which exhibited antibacterial activity against 23 pathogenic bacteria, to develop alternative agent of antibiotics. By investigating the microbiota from rocks on the seashore, we characterized and obtained various antibacterial material-producing bacteria. Thirty-one isolates belong to four genera and seven species, according to 16S rDNA sequence analysis, showed antibacterial activities against 23 pathogenic bacteria. The Identity of 16S rDNA sequences indicated three species of Bacillus, one species of Paenibacillus, one species of Pseudomonas and two species of Enterobacter. Two isolates were similar to Bacillus aerophilus, four isolates were similar to Bacillus pumilus, seven isolates were similar to Bacillus safensis, 15 isolates were similar to Paenibacillus polymyxa, respectively. In addition, one isolate was similar with Pseudomonas poae, one isolate was similar to Enterobacter asburiae, and one isolate was similar to Enterobacter ludwigii, respectively. Variations of antibacterial activity and level among the same species were indicated the diverse strains of isolates. Vibrio vulnificus showed the highest degree of growth inhibition by 29 isolates. Further studies regarding antibacterial materials and bacteria suggest that development of probiotic strains or alternative agents to antibiotics.

• Journal of Life Science
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• v.34 no.8
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• pp.540-547
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• 2024

The continuous use of polymer materials has exacerbated waste and environmental challenges, spurring a growing interest in eco-friendly polymers, especially biodegradable polymers. These polymers are gaining attention for their potential as antimicrobial agents, particularly in fields like food packaging a need further underscored by the recent COVID-19 pandemic. This study focuses on the development of an antibacterial polymer by combining poly-butylene adipate terephthalate (PBAT) with zinc pyrithione (ZnPt). The antibacterial properties were assessed through turbidity analysis, the shaking flask method, and the film adhesion method. The antibacterial activities of the composites with varying ZnPt% (w/w) contents (0, 0.1, 0.3, and 0.5) were evaluated against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). Results revealed that even at a low concentration of 0.1% (w/w), the composites demonstrated significant antibacterial activity against both Gram-positive bacteria (S. aureus) and Gram-negative bacteria (E. coli). Composites with ZnPt concentrations of 0.3% (w/w) or higher achieved over 99.999% antibacterial efficacy. Field emission scanning electron microscopy (FE-SEM) analysis of the fracture surfaces of the composites confirmed the uniform distribution of ZnPt particles, ranging from 1-4 ㎛. Further FE-SEM analysis of bacterial suspensions exposed to the composite surfaces showed clear evidence of cell wall destruction in both E. coli and S. aureus. As an antimicrobial biodegradable polymer, PBAT-ZnPt composites show great promise for applications in various sectors, including food packaging.

• YAKHAK HOEJI
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• v.44 no.4
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• pp.315-317
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• 2000

The in vitro activities of DA-074, a new cephalosporin against 34 various standard strains and its in vivo efficacies against 6 important strains were obtained. DA-074 showed two fold enhanced in vitro antibacterial activity against some Pseudomonas aeruginosa compared to Ceftazidime and more than 2 fold in vivo efficacy against Staphylococcus aureus Smith, Klebsiella pneumoniae 1 and Escherichia coli KC-14, compared to Cefpirome. DA-074 might be a good candidate for further evaluations.

• Journal of Plant Biotechnology
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• v.49 no.4
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• pp.339-346
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• 2022

This study investigates the antibacterial and antioxidant activities of the ethanol extract of Acer tegmentosum Maxim (EATM) against Staphylococcus aureus. The total polyphenol and flavonoid content, 1,1-diphenyl-2-picryl hydrazyl (DPPH) and 2,2'-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) radical scavenging effect, and reducing power of the ferric reducing antioxidant power (FRAP) method were measured to verify the antioxidant activity of the EATM. The antibacterial activity against S. aureus using the EATM was verified by the paper disc method, minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC) methods. The total polyphenol and flavonoid contents were 266.66 ㎍ GAE/mg and 6.46 ㎍ QE/mg, respectively. The DPPH and ABTS radical scavenging activity showed a concentration-dependent scavenging activity. The RC₅₀ values of the EATM were 21.49 and 12.81 ㎍/mL, respectively. A FRAP analysis was conducted for evaluating the reducing power of the EATM and an efficacy of 0.73 ± 0.19 mM FeSO₄ E/mg was observed. The antibacterial activity of EATM against S. aureus, determined using the paper disc method, showed an inhibitory ring of 3 mm at 2 mg. The MIC was confirmed at a concentration of ≥ 16 mg/mL, while the MBC was confirmed at 32 mg/mL. As the EATM shows antioxidant and antibacterial activities against S. aureus, it can be used as an effective antidote against atopic dermatitis.