• Journal of Microbiology and Biotechnology
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• v.20 no.12
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• pp.1735-1743
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• 2010

The full-length genes gyrB (2,415 bp), parC (2,277 bp), and parE (1,896 bp) in Edwardsiella tarda were cloned by PCR with degenerate primers based on the sequence of the respective quinolone resistance-determining region (QRDR), followed by elongation of 5' and 3' ends using cassette ligation-mediated PCR (CLMP). Analysis of the cloned genes revealed open reading frames (ORFs) encoding proteins of 804 (GyrB), 758 (ParC), and 631 (ParE) amino acids with conserved gyrase/topoisomerase features and motifs important for enzymatic function. The ORFs were preceded by putative promoters, ribosome binding sites, and inverted repeats with the potential to form cruciform structures for binding of DNA-binding proteins. When comparing the deduced amino acid sequences of E. tarda GyrB, ParC, and ParE with those of the corresponding proteins in other bacteria, they were found to be most closely related to Escherichia coli GyrB (87.6% identity), Klebsiella pneumoniae ParC (78.8% identity), and Salmonella Typhimurium ParE (89.5% identity), respectively. The two topoisomerase genes, parC and parE, were found to be contiguous on the E. tarda chromosome. All 18 quinolone-resistant isolates obtained from Korea thus far did not contain subunit alternations apart from a substitution in GyrA (Ser83$\rightarrow$Arg). However, an alteration in the QRDR of ParC (Ser84$\rightarrow$Ile) following an amino acid substitution in GyrA (Asp87$\rightarrow$Gly) was detected in E. tarda mutants selected in vitro at $8{\mu}g/ml$ ciprofloxacin (CIP). A mutant with a GyrB (Ser464$\rightarrow$Leu) and GyrA (Asp87$\rightarrow$Gly) substitution did not show a significant increase in the minimum inhibitory concentration (MIC) of CIP. None of the in vitro mutants exhibited mutations in parE. Thus, gyrA and parC should be considered to be the primary and secondary targets, respectively, of quinolones in E. tarda.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.8
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• pp.967-972
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• 2006

The antioxidative and antimicrobial activities were determined on the mushroom (Sarcodon aspratus) extracts in order to find out new food functional components. The antioxidative activities of water and ethanol extracts from the Sarcodon aspratus were measured by peroxide values (POV), electron-donating ability (EDA) using 1,1-diphenyl-2-picryl hydroxyl (DPPH), nitrite-scavenging ability and superoxide dismutase-like activity (SODA) by pyrogallol. The antioxidative activity of the ethanol extract measured by POV was higher than those of the water extract, BHT, and ${\alpha}-tocopherol$. The EDA of the water extract and ethanol extract using DPPH showed the highest values of 76.94% and 73.06%, respectively. The nitrite-scavenging abilities (pH 1.2, 1,000 ppm) of the water and ethanol extracts were 72.61% and 62.69%, respectively, and the nitrite-scavenging ability of the water extract was higher than that of the ethanol extract in all pH values. The SODA of the ethanol extract was higher than that of the water extract. The Sarcodon aspratus extracts had antimicrobial effects on Listeria monocytogenes and Staphylococcus aureus.

• Journal of the East Asian Society of Dietary Life
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• v.19 no.4
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• pp.570-578
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• 2009

The present study was conducted to investigate the antioxidant and antimicrobial activities of green tea at different harvest time. The leaves were collected in late March(Ilro), early April(Okro and Ujeon), late April(Sejak), and early May(Eoksu and Hanra). The total polyphenol content of Sejak was highest (28.87mg TAE/g). Electron donating abilities toward $\alpha$,$\alpha$-diphenyl-$\beta$-picyryl hydrazyl (DPPH) radical were approximately 80%. SOD-like activities were above 30%, where ujeon showed the highest activity ($38.95{\pm}0.96%$). The nitrite scavenging ability was pH-dependent and shown to be highest at pH 1.2, and lowest at pH 6.0. The inhibitory effects against the angiotensin I converting enzyme were over 85%, except for Okro ($58.22{\pm}4.66%$) and Hanra ($77.96{\pm}3.83%$). The tyrosinase inhibition rate increased with harvest time. Okro showed the highest caffeine content ($3.86{\pm}0.32%$) and had the highest antimicrobial activities against Listeria monocytogenes, Staphylococcus aureus, Escherichia coli, and Salmonella typhimurium. The combined results of this work revealed that the antioxidant and antimicrobial activities of green tea were independent of harvest time.

• Journal of the East Asian Society of Dietary Life
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• v.22 no.1
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• pp.109-119
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• 2012

This study analyzed the antibacterial activity of the ethanol extract of Schizandra chinensis Baillon against food pathogenic microorganisms to determine its capabilities as a natural antimicrobial agent. A paper disc diffusion test, minimum inhibitory concentration (MIC) determination, and time-kill assay showed that the ethanol extract strongly inhibits the growth of Listeria monocytogenes, Bacillus cereus, Escherichia coli O157:H7, and Pseudomonas aeruginosa. Release of cytoplasmic ${\beta}$-galactosidase was detected in E. coli, E. coli O157:H7, S. aureus, and P. aeruginosa treated with the ethanol extract. An increase of outer membrane permeability caused by the ethanol extract was also observed. An outward flow of cell constituents was detected in the Gram negative strains treated with the ethanol extract. These results imply that the inner and outer membranes of cells were partially destroyed and cell constituents were released by the treatment of the S. chinensis Baillon ethanol extract. The results of this study indicate that ethanol extract of S. chinensis Baillon evidences a fairly good antibacterial effect.

• YAKHAK HOEJI
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• v.40 no.5
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• pp.608-615
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• 1996

6-[(N-3,4-Difluorophenyl)amino]-7-chloro-5,8-quinolinedione(RCK4) was tested for antifungal activities, against systemic infections with Candida albicans in normal mice. The therapeutic potential of RCK4 had been assessed in comparison with ketoconazole and fluconazole. RCK4 had $ED_{50},\;0.30{\pm}0.14$ but ketoconazole and fluconazole had $ED_{50},\;8.00{\pm}0.73,\;10.00{\pm} 0.43mg/kg$ respectively. Intraperitoneally administered RCK3 at the $ED_{50}$ for 7 days and 14 days reduced Candida albicans colony count in the kidneys and liver as well as ketoconazole and fluconazole at these $ED_{50}$. And administered RCK4 at the $ED_{50}$ for 14 days improved survival rates as well as ketoconazole. Acute oral toxicity studies of RCK4 were carried out in ICR mice of both sexes. These acute oral toxicities of RCK4 were low and $LD_{50}$ values were over 2,850mg/kg in ICR mice. The genotoxicities of RCK4 had been evaluated. RCK4 was negative in Ames test with Salmonella typhimurium and chromosomal aberration test in CHL cells. The clastogenicity was tested on the RCK4 with in vivo mouse micronucleus assay. RCK4 did not show any clastogenic effect in mouse peripheral blood and was negative in mouse micronucleus assay. These results indicate that RCK4 has no genotoxic potential under these experimental conditions.

• Journal of Life Science
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• v.17 no.10
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• pp.1368-1373
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• 2007

Inhibitory effects of several solvent fractions from soybean on mutagenicity using Salmonella typhimurium TA 100 in Ames test and growth of human cancer cells (AGS gastric adenocarcinoma, Hep 3B hepatocellular cancinoma and HT-29 colon cancer cells) were studied. The treatment of dichloromethane and ethylacetate fractions (2.5 mg/assay) extracted from soybean to Ames test system inhibited aflatoxin $B_1\;(AFB_1)$ induced mutagenicity by 83%, respectively, and showed a higher antimutagenic effect than other solvent fractions. In case of N-methyl-N#-nitro-N-nitrosoguamidine (MNNG) induced mutagenicity, the ethylacetate fraction showed the highest inhibitory effect (by 67%) among solvent extracts, although the inhibitory effect was not stronger compared with $AFB_1$ induced mutagenicity. In sulforhodamine B (SRB) assay, the treatment of ethylacetate fraction (2 mg/assay) significantly inhibited the growth of AGS, Hep 3B and HT-29 cancer cells by 66%, 73% and 77%, respectively, followed with the intermediate and dichloromethane fractions. These results indicated that soybean fraction extracted with ethylacetate had higher inhibitory effects on $AFB_1$ and MNNG in Ames test and growth inhibition activity to human cancer cells was appeared, suggesting that soybean fraction extracted with ethylacetate may contain the biologically active compounds.

• Korean Journal of Food Science and Technology
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• v.29 no.6
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• pp.1228-1235
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• 1997

This study was conducted to standardize the proper ingredient ratios of chinese cabbage kimchi by the sensory evaluation, chemical properties, and functional properties of antimutagenic effect and inhibitory effect on the growth of cancer cells from the ratios obtained from literatures. The standardized ratios of ingredient from the literatures was 13.0 of radish, 2.0 of green onion, 3.5 of red pepper powder, 1.4 of garlic, 0.6 of ginger, 2.2 of anchovy juice, 1.0 of sugar and the final salt concentration 2.7 in the proportion of 100 salted chinese cabbage. The standardized ratio of the ingredients exhibited better overall acceptability and less moldy smell and moldy flavor than any other ratio of ingredient in the sensory evaluation. The standardized kimchi with the above ratios of the ingredients, at final salt concentration of 2.5%, showed high reducing sugar contents and Leuconostoc sp. counts. All juices of the chinese cabbage kimchi showed not only high antimutagenicity against aflatoxin $B_1$ in Salmonella typhimurium TA100 but also strong inhibitory effect on the growth of AGS human gastric adenocarcinoma cells in SRB assay, especially these functional properties were the most effective at each standardized ratio of the ingredients. From the taste, chemical and functional properties, the standardized ratios of ingredients was 13.0 radish, 2.0 green onion, 3.5 red pepper powder, 1.4 garlic, 0.6 ginger. 2.2 anchovy juice, 1.0 sugar and the final salt concentration 2.5 in the proportion of 100 salted chinese cabbage.

• Journal of Applied Biological Chemistry
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• v.55 no.2
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• pp.117-121
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• 2012

Biological activities of the hot water and ethanol extracts from Opuntia humifusa cladodes were investigated. 1,1-diphenyl-2-picryl hadrazyl (DPPH) electron donating ability of hot water and ethanol extracts was 79.07 and 82.54%, respectively. Hot water extract generally showed better cytotoxic activity than ethanol extract against each cell line. HeLa and AGS cell lines treated with hot water extract had more than 50% cytotoxic activities. Based on the antimicrobial activities against four microbial strains, both extracts inhibited growth of Staphylococcus aureus KCCM 11593, whereas affected cell growth of three other microorganisms, Escherichia coli (KCCM 11234), Pseudomonas aeruginosa (ATCC 27853), and Salmonella typhimurium (ATCC 11862), in proportion to the concentration of extracts. The inflammatory activities against hot water extract (34.31%) showed higher than that of ethanol extract (25.59%). The effect of extracts on 3T3-L1 preadipocytes differentiation showed that differentiation of treated group with 80 and 100 ${\mu}g/mL$ of hot and ethanol extracts were increased more than treated group with isobutyl methyl xanthine (IBMX) + dexamethasone. These results indicate that the O. humifusa cladodes extracts can be used as a functional material due to their effective biological activities.

• Korean Journal of Veterinary Research
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• v.42 no.1
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• pp.45-54
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• 2002

The study was carried out to characterize the pharmacokinetics after intravenous (iv, 20 mg/kg) and oral (p.o. 100 mg/kg) administration as oxytetracycline (OTC) and tiamulin (TIA) mixture in swine and to determine interaction between OTC and TIA against various pig pathogenic bacteria. The antibacterial effects of OTC in combination with TIA in vitro showed synergistic effect against Salmonella typhimurium 1925, Pasteurella multocida Type A, P. multocida Type D, Krebsiella Pneumoniae 2001, K. Pneumoniae 1560, K. Pneumoniae 2208, Haemophillus pleuropneumonia S 2, and H. pleuropneumonia S 5, but against additive effect E. coli K88ab and S. choleraesuis on the basis of fractional inhibitory concentration (FIC) index. On the while, after i.v. and p.o. administration of OTC and TIA mixture, each OTC and TIA concentrations in plasma were fitted to an open two-compartment model. After i.v. administration of OTC-TIA mixture, the mean distribution half-life ($T_{1/2{\alpha}}$) of OTC and TIA in plasma showed 0.29 h and 0.17 h, and the mean elimination half-life ($T_{1/2{\beta}}$) of those was 4.36 h and 6.64 h, respectively. The mean volume of distribution at steady state ($Vd_{ss}$) of OTC and TIA was $0.85{\ell}/kg$ and $2.44{\ell}/kg$, respectively. After oral administration of OTC and TIA mixture, the mean maximal absorption concentrations ($C_{max}$) of OTC and TIA were $0.60{\mu}g/m{\ell}$ at 1.07 h ($T_{max}$) and $1.68{\mu}g/m{\ell}$ at 1.85 h ($T_{max}$), respectively. The mean elimination half-life ($T_{1/2{\beta}}$) of those showed 6.84 h and 6.36 h. In conclusion, we could suggest in this study that the combination of OTC and TIA may be recommended for the antibacterial therapy against polymicrobial infections, and both OTC and TIA showed large distribution to tissues and high $C_{max}$ after p.o. administration.

• Korean Journal of Food Science and Technology
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• v.48 no.5
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• pp.437-444
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• 2016

Rapid and reliable identification of microorganisms is important to maintain food quality and to control safety. MALDI-TOF MS-based identification methods are relatively fast and simple compared to other conventional methods including gram staining and biochemical characterization. A colony on subcultured media can be directly prepared on the analysis plate without further complex treatments. In this study, we confirmed the applicability of MALDI-TOF MS-based identification of foodborne pathogens such as Salmonella Enteritidis/Typhimurium, Staphylococcus aureus, Vibrio parahaemolyticus, Clostridium perfringens, Listeria monocytogenes, Yersinia enterocolitica, Bacillus cereus, Campylobacter jejuni, Campylobacter coli, and Cronobacter sakazakii on the Korea Food Standard Codex. MALDI-TOF MS data of the pathogenic reference strains were incorporated into a commercial MicroID (ASTA Inc.) database. Other pathogenic reference strains and seven isolates from various food samples were correctly identified to the species level by using the MicroID database. In conclusion, MALDI-TOF MS is comparable with commercial biochemical identification.