• Journal of Food Hygiene and Safety
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• v.27 no.1
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• pp.63-67
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• 2012

Antibiotic resistance in animal isolates of enterococci is a public health concern, because of the risk of transmission of antibiotic-resistant strains or resistance genes to humans through the food chain. This study investigated phenotypic and genotypic resistances profile of tetracycline in 245 $Enterococcus$ isolates from bovine milk. A total of 245 enterococci were isolated from 950 milk samples. The predominant strain was $E.$ $faecalis$ (n = 199, 81.2%) and $E.$ $faecium$ (n = 25, 10.2%). $E.$ $avium$ (n = 7, 2.9%), $E.$ $durans$ (n = 6, 2.5%), $E.$ $gallinarum$ (n = 4, 1.6%), and $E.$ $raffinosus$ (n = 4, 1.6%) were also isolated. Of the 245 enterococcal isolates 76.3% (n = 187) displayed tetracycline resistance (${\geq}16{\mu}g/ml$). Of the 187 tetracycline-resistant isolates, 83.4% (n = 156), 16.1% (n = 30), and 26.7% (n = 50) possessed the genes $tet$(M), $tet$(L), $tet$(S) respectively. While 3.2% (n = 6) of the tetracycline-resistant isolates possessed all three genes $tet$(M) + $tet$(L) + $tet$(S), 8.6% (n = 16), 16.0% (n = 30), and 2.7% (n = 5) of them possessed two genes $tet$(M) + $tet$(L), $tet$(M) + $tet$(S), and $tet$(L) + $tet$(S) respectively. The tetracycline resistance pattern investigated in this study was attributable mainly to the presence of $tet$(M).

• Journal of The Korean Society of Inherited Metabolic disease
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• v.2 no.1
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• pp.77-79
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• 2002

The urea cycle, consisting of a series of six enzymatic reactions, plays key roles to prevent the accumulation of toxic nitrogenous compound and synthesize arginine de novo. Five well characterized diseases have been described, resulting from an enzymatic defect in the biosynthesis of one of the normally expressed enzyme. This presentation will focus on two representative diseases; ornithine transcarbamylase(OTC) deficiency and citrullinemia(argininosuccinate synthetase deficiency). OTC deficiency is one of the most common inborn error of urea cycle, which is inherited in X-linked manner. We identified 17 different mutations in 20 unrelated Korean patients with OTC deficiency; L9X, R26P, R26X, T44I, R92X, G100R, R141Q, G195R, M205T, H214Y, D249G, R277W, F281S, 853 del C, R320X, V323M and 10 bp del at nt. 796-805. These mutations occur at well conserved nucleotide sequences across species or CpG hot spot. The L9X and R26X lead to the disruption of leader sequences, required for directing mitochondrial localization of the OTC precursor. Their phenotypes are severe, and neonatal onset. The G100R, R277W and V323M mutations were uniquely identified in patients with late onset OTC deficiency. The other genotypes are associated with neonatal onset. Out of 20 patients with OTC deficiency, only 6 patients are alive; two were liver transplanted, and normal in growth and development at 2, 4 years after transplantation respectively. Citrullinemia is an autosomal recessive disease, caused by the mutations in the argininosuccinate synthetase(ASS) gene. We identified in 3 major mutations in 11 unrelated Korean patients with citrullinemia; G324S, $IVS6^{-2}$ A to G, and 67 bp ins at nt 1125-1126. Among these, the 67 base pair insertion mutation is novel. The allele frequency of each mutation is; G324S(45%), IVS6-2 A to G(32%), and 67 base pair insertion(14%). All patients are diagnosed at neonatal or infantile age. Interestingly, two patients presented with stroke like episode. Out of 11 patients, 5 patients died. Among 6 patients alive, one patient was successfully liver transplanted.

• Journal of Life Science
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• v.15 no.3 s.70
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• pp.434-438
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• 2005

In the previous study, we isolated a myulchikinase (MK), which has fibrinolytic activity and cytotoxicity to the tumor cell line, from myl- chi-jeot-gal. In this study, the effect of NaCl concentration, metallic ions, pH, temperature, and plasminogen on the activity of MK was analysed. The MK activity was maintained at least $80\%$ activity up to $30\%$ NaCl, which indicates that the enzyme may be halotolerant. The optimal pH and temperature were 8 and $40^{\circ}C$, respectively. The fibrinolytic activity of MK was completely inhibited with 0.5 mM $Hg^{2+}$ and inhibited to $50^{\circ}C$ with 1 mM $Cu^{2+}\;and\;Zn^{2+}$. The MK showed strong activity in plasminogen- rich fibrin plate but not in plasminogen-free fibrin plate. The result indicates that the MK may be a plasminogen activator type fibrinolytic enzyme.

• Journal of Life Science
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• v.14 no.4
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• pp.683-688
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• 2004

A bacteriocin-producing lactic acid bacteria was isolated from Kimchi on MRS selective media with the use of Lactobacillus delbrueckii subsp. delbrueckii as an indicator strain. The strain YH-10 was identified as Lactococcus lactis subsp. lactis through the API test. The crude bacteriocin (freeze-dried 50% ammonium sulfate precipitate of culture supernatant) produced by the strain was named as lacticin YH-10. Lacticin YH-10 showed the growth inhibitory activity against Gram positive pathogenic bacteria and other lactic acid bacteria. The bacteriocin was inactivated by proteases such as protamex and aroase AP-10 and partially inactivated by amylase, proteinase K, trypsin, and papain. The lacticin YH-10 remained its activity with the treatment of heat at 10$0^{\circ}C$ for 60 min or the changes of pH 2 to 11. However, the activity was lost at high pH combined with the exposure to 10$0^{\circ}C$. The bacteriocin production of the strain was started in the exponential phase and stopped in the stationary phase. The approximate molecular mass of the bacteriocin produced by the strain was approximate 14 kDa in the analysis on SDS-PAGE.

• Microbiology and Biotechnology Letters
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• v.20 no.5
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• pp.574-582
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• 1992

Exo-xylanase encoded by the xylA gene of Bacillus stearothermoPhillus was produced from Escherichia coli ]M109 carrying a recombinant plasmid pMGL Synthesis of the enzyme was observed to be cell-associated, and about 94% of the enzyme synthesized was located in the cytoplasmic region. The maximum production was attained when the E. coli strain was grown at $37^{\circ}C$ for 8 hours on the medium containing 0.5% fructose, 1.0% tryptone, 1.0% sodium chloride, and 0.5% yeast extract. The exo-xylanase was purified to homogeneity using a combination of salting out with ammonium sulfate, DEAE-Sepharose CL-6B ion exchange chromatography, Sephadex G-IOO gel filtration, and Sephadex G-150 gel filtration. The' purified enzyme was most active at pH 6.0 and $45^{\circ}C$. $Ca^{2+}$ and $Co^{2+}$ activated the exo-xylanase activity by about 20% while $Ag^{2+}$, $Fe^{2+}$, $Mg^{2+}$ and $Zn^{2+}$ inhibited the enzyme activity by up to 60%. The $K_m$, value on p-nitrophenyl-$\beta$-D-xylanopyranoside was 2.75 mM. The enzyme had a pI value of 4.7. The estimated molecular weight of the native protein was 200,000 daL SDS-polyacrylamide gel electrophoresis analysis suggested that the native enzyme was a trimer composed of three identical 66,000 da!. polypeptides. The purified enzyme efficiently converted all the xylo-oligosaccharides tested to xylose. It was also confirmed that the enzyme split xylans in an exo-manner even though the degree of hydrolysis was fairly low. The xylanolytic enzyme was, therefore, classified to be one of the few bacterial exo-xylanases lacking transferase activity.

• Journal of Animal Science and Technology
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• v.46 no.6
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• pp.909-916
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• 2004

CCAAT/enhancer binding proteins(C/EBP) are a group of transcription factors expressed during preadipocyte differentiation. In the C/EBPs, C/EBPa plays an important role in lipid deposition and adipocyte differentiation. In this studies, we report the identification, characterization, and expression of a Hanwoo CIEBP$\alpha$ The Hanwoo C/EBP$\alpha$DNA includes a 1059 bp open reading frame encoding a protein of 353 amino acids. The CIEBPa amino acid sequences of the Hanwoo show strong conservation with the corresponding sequences reported in other species. The distribution of C/EBP$\alpha$ mRNA in various tissues of Hanwoo aged 12 months were investigated using Northern blotting analysis. The highest expression was detected in adipose tissue and more lower expression was detected in colon and lung. We also identified expression of C/EBPa mRNA in Hanwoo sirloin and adipose tissue aged 12, 26, and 30 months by real-time RT-PCR. The higest expression were detected at 26 months in the sirloin and at 12 and 26 months in the adipose tissue.

• Applied Chemistry for Engineering
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• v.9 no.4
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• pp.542-547
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• 1998

Polyamine type polymer flocculants were synthesized and their characterization, viscosity and flocculation studies were conducted. In order to increase the molecular weight of polyamine flocculant which was prepared by polycondensation reaction from dimethylamine and epichlorohydrin, a small amount of 1,6-hexanediamine was employed. The incorporation of 1,6-hexanediamine up to 5.5 mole % replacing corresponding part of dimethylamine gave a branched type polyamine sample with increased intrinsic viscosity ([${\eta}$]=0.46 in 1 wt % aqueous NaCl solution). The amount of 1,6-hexanediamine above 5.5 mole %, however, resulted in gelation during polymerization. Utilizing raw water from Maegok potable water treatment plant, it was found that the addition of polyamine flocculant at a concentration of 1 mg/L level could reduce the amount of polyaluminum chloride (PAC) inorganic flocculant by half (15 mg/L). It was also observed that the incoporation of polyamine flocculant at 1 mg/L level was effective in the higher pH raw water, while PAC inorganic flocculating agent alone was not effective.

• Korean Journal of Clinical Laboratory Science
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• v.50 no.2
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• pp.100-109
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• 2018

The emergence and dissemination of multidrug-resistant (MDR) Acinetobacter baumannii isolates have been reported worldwide, with most of these possessing the ability to form biofilms. Biofilm formation is an important virulence factor associated with the resistance to disinfection and desiccation. This study examined the genetic basis of antimicrobial resistance mechanisms of biofilm-forming A. baumannii clinical isolates. Imaging and quantification of biofilms were performed by a crystal violet assay and 46 biofilm-forming A. baumannii isolates were selected. Subsequently, 16 isolates belonging to different clones were identified using REP-PCR, and detection of the antimicrobial determinants in the isolates was carried out. The 16 isolates included 9 non-MDR and 7 MDR isolates. The mean biomass $OD_{560}$ values of the non-MDR (0.96) and MDR (1.05) isolates differed but this difference was not significant. In this study, most biofilm-forming MDR A. baumannii isolates contained various antimicrobial resistance determinants ($bla_{OXA-23}$, armA, and mutations of gyrA and parC). On the other hand, most biofilm-forming non-MDR A. baumannii isolates did not contain antimicrobial resistance determinants. These results suggest that there is little correlation between the biofilm-forming ability and antimicrobial susceptibility in A. baumannii isolates. In addition, the emergence of MDR A. baumannii clinical isolates is generally caused by mutations of the genes associated with antimicrobial resistance and/or the acquisition of various antimicrobial resistance determinants.

• Journal of fish pathology
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• v.22 no.1
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• pp.53-65
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• 2009

Tenacibaculum maritimum (formerly Flexibacter maritimus) is the aetiological agent of an ulcerative and necrotic disease commonly called tenacibaculosis in marine fish. Tenacibaculosis is an economically important disease in a great variety species in Jeju Island cultured fish and leading to this pathogen initially affected by skin, mouth, fins, tail causing severe necrotic and ulcerative lesions on the body surface. In the present study, A-7 strain was isolated from Paralichthys olivaceus showing symptoms of tenacibaculosis and identified as T. maritimum by morphological, biochemical and molecular biological analysis. T. maritimum A-7 is experimentally infected through immersion route in Paralichthys olivaceus which the disease outbreaks in land-based fish tanks of Jeju Island. Up to data a number of treatments proposed for the tenacibaculosis outbreaks are based on the immersion administration of drugs in tank. Oxytetracycline is the most widely used disinfectants in fish farms. However, most of fish farms manager and consumers have expressed concern as bioaccumulation in tissue and its environmental. In addition, this antimicrobial compounds is expensive in fish farmers. The overcome of this problem is desired the application of natural plant derived products. To obtain as 70% EtOH extract antimicrobial compounds against tenacibaculosis from 35 species of Jeju Island native plants were screened for antimicrobial activity against T. maritimum. In the present study were identified most of the plant extracts were better antimicrobial activity against T. maritimum.

• Microbiology and Biotechnology Letters
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• v.20 no.4
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• pp.377-383
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• 1992

Seven strains of Bacillus thuringiensis were isolated from soil in Korea and characterized. The isolates were named HL-8, 10, 12, 13, 14, 15 and 16 which produced parasporal crystals and endospores in their cells. The biochemical characteristics of the seven isolates were only minor different in specific chracteristics to the known serotypes of Bacillus thuringiensis. The number of the plasmid DNA elements from the isolates were studied. The computerized molecular weights of the six plasmid elements in the HL-8 and HL-lO strains were from 3.01 to 15.1 Md, four plasmid elements in the HL-12 were from 5.4 to 21.9 Md, four plasmid elements in HL-13 were from 5.1 to 20 Md, three plasmid elements in HL-15 were from 3.4 to 11.3 Md and three plasmid elements in the HL-16 were from 2.4 to 20.1 Md. The seven isolates showed resistances to ampicillin, bacitracin, cephalothin, methicillin and penicillin G. The strains of HL-8, HL-lO, HL12, HL-14, HL-15 and HL-16 showed lethalities against Culex pipiens 3rd instar larvae. The HL8 and 14 strains showed 100% lethality to the larvae within 48 hours. HL-13 strain did not have toxicity against the larvae.