• Korean Journal of Veterinary Service
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• v.21 no.3
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• pp.261-266
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• 1998

A method for the determination of noboviocin in milk was presented by high performance liquid chromatography(HPLC). The novobiocin in the spiked sample was extracted with methanol and evaporated under vacuum. After evaporating, the residue was mixed with distilled water for 2$m\ell$, filtrates with 0.45$\mu\textrm{m}$ acrodisc was injected into HPLC. The results obtained were as follows ; 1. The calibration curve of novobiocin was showed constantly linear(r 0.999) in the range of 100~500ng/$m\ell$. 2. The mean recovery rate of novobiocin from the spiked milk sample were 88~98%. 3. The coefficients of variation were 2.6~5.8% 4. The lowest detectable limit of novobiocin was 25ppb.

• Korean Journal of Food Science and Technology
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• v.28 no.2
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• pp.279-284
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• 1996

To develop a selective medium for the isolation and the detection of leuconostocs from the various samples including fermented vegetables, ten strains of leuconostocs and seven strains of lactobacilli were tested for their sensitivity to various antibiotics. The basal-medium containing 5 ${\mu}g/ml$ of novobiocin inhibited the growth of lactobacilli completely, but not that of leuconostocs. On the basis of this result, a new selective medium was developed and to be named NLS medium. This medium contains 1% Tryptone (Difco), 0.1% Yeast Extract (Difco), 2% sucrose, 0.1% Beef Extract (BBL), 0.5% sodium acetate, 0.2% ammonium sulfate, 0.01% magnesium sulfate, 0.2% dipotassium phosphate, 0.05% sorbic acid, 75 ppm sodium azide (Sigma), 0.1% (vol/vol) Tween 80, 30 ${\mu}g/ml$ of Vancomycin (Sigma), 5${\mu}g/ml$ of Novobiocin (Sigma), 0.5${\mu}g/ml$ of cysteine HCI, and 1.5% Agar (Difco). All of the eighty six isolates obtained from some foodstuffs were identified as members of the genus Leuconostoc. Comparative counts with the MRS, PES, LUSM, and NLS medium indicated that the recovery percent was lower than other selective media. Therefore, this result suggested that NLS medium was suitable for the isolation of leuconostocs, but not for counting or enumerating.

• The Korean Journal of Zoology
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• v.36 no.3
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• pp.367-372
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• 1993

We have found a protein kinase activity that is tightly associated with type II DNA topoisomerase purified from regenerating rat liver. The activities of protein kinase and topoisomerase II were not separable when the enzyme was subjected to analytical chromatographies (Hydroxyapatite, phosphocellulose, and double strand DNA cellulose) and glycerol gradient sedimentation. The kinase activity from purified rat topoisomerase II was also inactivated by the topoisomerase II inhibitors such as N-ethylmaleimide or novobiocin. The evidences, however, do not rule out a possibility that the kinase activity resides in a polypeptide other than the topoisomerase II protein. The topoisomerase II-associated protein kinase required Mg++ for its activity, and this requirement was not substituted by any other mono- or divalent ions. Histone H1 act as a strong stimulator and a good substrate for the kinase activity and other histones and ${\alpha}$-casein could not substitute the effect of histone H1.

• Korean Journal of Food Science and Technology
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• v.44 no.3
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• pp.263-268
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• 2012

Novobiocin is a coumarin-containing antibiotic, and has a longer half-life in various animals than other veterinary medicines. A simple and rapid high-performance liquid chromatography assay for the determination of residual novobiocin levels in chicken, beef and milk has been developed and validated. The separation condition for HPLC/UVD was optimized by a MG II $C_{18}$ (4.6 mm $ID{\times}250$ mm, 5 ${\mu}m$) column with 0.1% formic acid in $H_2O$/0.1% formic acid in Acetonitrile (40/60, v/v) as the mobile phase at a flow rate of 1.0 mL/min and the detection wavelength was set at 340 nm. Residues were extracted from tissue by blending with methanol. After liquid-liquid partitioning, lipid materials were removed with n-hexane and purification as Silica (1 g, 6 mL) cartridge with 10 mL acetone/dichloromethane (10/90, v/v). Limit of quantification and linearity performed by the analytical method were 0.02 mg/kg and 0.999 ($r^2$), and the recovery range was $88.8{\pm}5.6-100.3{\pm}4.4$, $88.8{\pm}7.2-97.0{\pm}3.2$ and $88.1{\pm}4.3-92.8{\pm}3.6%$. It is expected that this analytical method with regards to novobiocin in chicken, beef and milk could be applied as an official method to administer food safety on veterinary medicines.

• Journal of fish pathology
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• v.7 no.1
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• pp.23-36
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• 1994

A total of 8 strains of Staphylococcus epidermidis isolated in land-marine tank system of Kyongnam and Kyongbuk. Prefecture were tested for the biological and biochemical characteristics. These strains were isolated from pathologic specimens of cultured flounder. Paralichthys olivaceus. Growth of the isolates was good on BHIA, HIA. Staphylococcus No. 110 and ETGP. Growth was good at NaCl concentration between 2.0 and 3.0%, about $30^{\circ}C$ and at pH values about 7.0. DNase and coagulase production were negative, and all isolates except FSJ-2 strain were positive in hemolysis. Urease was positive reaction, and novobiocin resistance was negative. Acid was produced anaerobically from glucose and maltose. All isolates except FSJ-19 strain produced weakly were negative in anaerobic acid production from mannitol. Acid was produced aerobically from glucose, fructose, galactose, sucrose, maltose and dextrine. But all isolates were not gas production. In characterization of clinically isolates, four different biotype codes were obtained when the all isolated were tested simultaneously. Four different antibiotic susceptibility patterns were obtained. On the basis of these characteristics, the isolates were identified as Staphylococcus epidermidis.

• Journal of fish pathology
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• v.12 no.2
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• pp.115-121
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• 1999

MIC test of 16 chemotherapeutic agents was performed on 24 isolates of Edwardsiella tarda collected from flounders. They revealed resistance against combinations of ampicillin, amoxicillin, erythromycin, flumequine, doxycycline(DOXY), nalidixic acid, novobiocin, oxolinic acid, oxytetracycline(OTC), thiamphenicol(TP) and sulfonamide. Two strains carried transferable R plasmid encoding Otc Kanamycin Tp and Otc chloramphenicol Doxy Tetracycline Tp, respectively. The R plasmids were not similar each other on the basis of their digestion pattern of restriction endonuclease, suggesting distribution of different transferable R plasmid among E. tarda from flounders.

• Environmental Mutagens and Carcinogens
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• v.9 no.1
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• pp.13-22
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• 1989

The effect of novobiocin (NOV), and inhibitor of topoisomerase II, on ethyl methanesulfonate (EMS)-or bleomycin (BLM)-induced DNA repair synthesis was examined during the cell cycle of Chinese hamster ovary (CHO)-K1 cells. Three assays were employed in this study: cell survival, alkaline elution and unscheduled DNA synthesis. EMS was effective at killing CHO cells in G1 phase, wheras BLM preferentially killed cells in G2 and S phases. EMS induced the much more amount of DNA damage in G1 phase, while BLM induced in G2 phase than the other phases. The both of pre- and post-treatment with BOV inhibitied EMS- or BLM-induced DNA repair synthesis in G1 and G2 phases, and pretreatment with NOV inhibited more effectively than the post-treated group. These results suggested that CHO cells exhibited a differential sensitivity to cell lethality and DNA damage in relation to cell cycle according to used chemical agents, and that DNA topoisomerase II participated in an initial stage of DNA repair.

• Journal of Microbiology and Biotechnology
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• v.12 no.5
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• pp.826-828
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• 2002

In our previous studies, we have cloned and characterized a gene region from Bradyrhizobium japonicum ,which is involved in the synthesis of lipopolysaccharide (LPS). In this study, we have expanded the sequence analysis of the region and found an additional open reading frame (orf), which appeared to be divergently transcribed from the rfaF gene. Sequence alignment of the orf revealed a significant similarity with rfaD genes of Salmonella typhimurium , Escherichia coli, and Neisseria gonorrhoeae. These genes encode a heptose-6-epimerase, which catalyzes the interconversion of ADP -D -glycerol-D-manno-heptose to ADP-L-glycero-D-manno-heptose. This divergent organization of the rfaF and rfaD genes is different from that of other Gram-negative bacteria where two genes form an operon. A rfaD- mutant of E. coli was successfully transformed with plasmid constructs containing the rfaD gene of B. japonicum. Novobiocin sensitivity test showed that the rfaD gene from B. japonicum could complement the rfaD mutation in E. coli, which confirms the functionality of the cloned B. japonicum gene.

• Korean Journal of Veterinary Research
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• v.39 no.2
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• pp.376-382
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• 1999

A methicillin-resistant Staphylococcus aureus (MRSA) isolate was recovered from a 9-month-old female Shih-Tzu dog with canine distemper virus infection. We performed in vitro antimicrobial susceptibility test to determine the most effective antimicrobial drug against the isolate and thus, to emphasize its potential clinical importance in animal practices. Isolate was confirmed MRSA by oxacillin agar screening test. The isolate was fully resistant to all $\beta$-lactam antibiotics and was susceptible to glycopeptides. Of the other antibiotics, mupirocin, TMP/SMZ (trimethoprim-sulfamethoxazole), and chloramphenicol showed inhibitory effect at the concentration of 4x MIC. The MICs ranged 0.25->$128{\mu}g/ml$, and MBCs ranged 0.5->$128{\mu}g/ml$. The combined TMP/SMZ with cefamandole or novobiocin showed synergistic effect, whereas the combination of novobiocin plus cefamandole or teicoplanin resulted in antagonistic effects. Although MRSA in animals so far has been reported in the geographically limited countries, at least theoretically, it could be occurred in the future more frequently through either human or animal origin. The use of this combination may be of value in this situation. As with all antimicrobial agents, inappropriate or unnecessarily prolonged therapy may contribute to the emergence of resistance strains and loss of efficacy.

• Microbiology and Biotechnology Letters
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• v.13 no.4
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• pp.417-422
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• 1985

Streptococcus faecalis var. liquefaciens was examined for the presence of plasmid deoxyribonucleic acid. An analysis by agarose gel electrophoresis revealed the presence of at least four plasmids of approxymately 6.8, 5.2, 2.6, and 2.1 Mdal. Two plasmid cured strains were obtained by novobiocin treatment. SKR2, which lost 5.2 mdal plasmid (pSK2) and 2.1 Mdal plasmid(pSK4) was sensitive to lincomycin and erythromycin. However, all cured strains showed identical response as parental strain in sugar fermentation, temperature sensitivity, proteolytic activity, and liquefaction of gelatin. The results imply that pSK2 or pSK4 is associated with antibiotic resistance of Str. faecalis var. liquefaciens.