• Journal of Microbiology
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• v.44 no.6
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• pp.680-684
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• 2006

Twenty isolates resistant to seven quinolones were isolated from major rivers in Korea. All isolates had three mutations, Ser83$\rightarrow$Leu and Asp87$\rightarrow$Asn in GyrA and Ser80$\rightarrow$Ile or Ser80$\rightarrow$Arg in ParC and three isolates had an additional mutation Glu84$\rightarrow$Gly or Glu84$\rightarrow$Val in ParC. In addition, a clonal spread was not found in these isolates.

• Journal of Microbiology
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• v.45 no.6
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• pp.590-592
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• 2007

We report the isolation of Salmonella enterica serotype Typhimurium phage type DT104 (CCARM 8104) from swine in Korea. The CCARM 8104 isolate was resistant to nalidixic acid and showed reduced susceptibility to quinolones. The CCARM 8104 isolate had a missense mutation, Asp87Asn, in the quinolone resistance-determining region in gyrA and produced PSE-1. The CCARM 8104 isolate carried two different class 1 integrons, and the PSE-1 ${\beta}$-lactamase gene was inserted into a 1,200 bp class 1 integron. The presence of DT104 with pse-1 in an integron located in a plasmid and reduced susceptibility to quinolone in swine pose a significant threat of possible horizontal spread between swine and humans.

• Toxicological Research
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• v.8 no.1
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• pp.63-70
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• 1992

The present study was performed to evaluate whether the application of Fenbufen is reasonable for predicting the convulsive liability of the quinolone derivatives and to examine whether pentylenetetrazole (PTZ) can be used as a screening tool for their Central Nervous System (CNS) toxic pontential. The convulsive activity of the quinolones was markedly potentiated by the pretreatment of Fenbufen. In combination with Fenbufen, enoxacin (ENX), norfloxacin (XFLX), and ciprofloxacin (CPFX) provoked convlusions and subsequent death at the intravenous doses of 0.5mg/kg, 10mg/kg, and 40mg/kg, respectively, whereas ofloxacin (OFLX) and pefloxacin (PFLX) did not induce convulsions and death even at a relatively high dose of 100mg/kg iv.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1997.04a
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• pp.57-63
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• 1997

Animal and clinical investigations have shown that fluoroquinolones, new quinolone antibacterial agents (NQs), are well absorbed across the intestinal tract, with a bioavailability of 60-90% after oral administration. Although some types of carrier-mediated intestinal transport mechanisms have been reported for enoxacin (ENX), ofloxacin (OFLX) and sparfloxacin (SPFX), recent results using a human intestinal epithelial cell line, Caco-2, indicated a passive or nonsaturable transport of SPFX, one of the most hydrophobic NQs. The mechanism underlying the intestinal absorption of NQs is still largely unknown. The distribution of NQs into peripheral tissues including erythrocytes is very rapid and their tissue-to-plasma concentration ratios (Kp) are considerably larger than those of inulin (an extracellular fluid space marker), in spite of almost complete ionization of NQs at the physiological pH. Our findings suggest that OFLX and lomefloxacin (LFLX) are taken up by rat erythrocytes via a transport system common to that of a water-soluble vitamin, nicotinic acid.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1997.04a
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• pp.12-12
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• 1997

CFC-222 is a novel fluoroqinolone antibacterial agent synthesized and under development by the Cheil Jedang Corporation, Korea. CFC-222 exerts the antibacterial activity by inhibition of bacterial DNA gyrase leading to bactericidal action. In in vitro and in vivo preclinical testing, CFC-222 has been shown to possess a broad spectrum of antibacterial activity. In particular CFC-222 is very potent against Gram-positive bacteria such as Staphylococcus spp., Streptocuccus spp. (in particular penicillin G-resistant and -susceptible S. pneumoniae) and Enterococcus spp. when compared to other quinolones (ciprofloxacin, ofloxacin or lomefloxacin). CFC-222 also showed potent activity against the methicillin resistant clinical isolates of S. aureus (MRSA). Against Gram-negative bacteria (E. coli, Pseudomonas and Sarcina) the activity of CFC-222 was slightly weaker than that of ciprofloxacin, but was more potent than that of ofloxacin or lomefloxacin. In urinary systemic infections caused by both Gram-positive and -negative bacteria, CFC-222 demonstrated a potent therapeutic efficacy in particular against Cram-positive bacteria S. aureus, S. pyrogen 203 and S. pneumonia TypeIII.

• Biomolecules & Therapeutics
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• v.7 no.2
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• pp.164-169
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• 1999

The synthesis and antimicrobial activity of N-substituted glycol derivatives of Norfloxacin were described. Norfloxacin was treated with chloroacetyl chloride to yield chloroacetyl norfloxacin (1). This compounds was reacted with alkyldiamines to afford bivalent ligand quinolone carboxylic acids (2-6), which was added to pivaloyloxymethyl chloride to give bivalent ligand pivaloyloxymethyl quinolone carboxylates (7-11). Chloroacetyl norfloxacin (1) treated with alkylamines to obtain monovalent ligand quinolone carboxylic acids (12-15), which was reacted with pivaloyloxymethyl chloride to get monovalent ligand pivaloyloxymethyl quinolone carboxylates (16-19). Free carboxylic quinolones (2-6, 12-15) showed little stronger activities to their pivaloyloxymethyl esters (7-11, 16-19). In monovalent ligand quinolone analogues, longer a1kyl chain com-pounds showed stronger activities than shorter one.

• Journal of Microbiology and Biotechnology
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• v.15 no.2
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• pp.421-424
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• 2005

Effect of antibiotics belonging to three different groups, including third generation cephalosporins, aminoglycosides, and quinolones, on the outer membrane protein (OMP) profile of Klebsiella pneumoniae was examined. It was found that a new OMP (porins) of 40 kDa molecular mass was expressed in Klebsiella pneumoniae, when grown in the presence of ceftazidime, whereas new proteins with 30 kDa and 22 kDa masses were detected in the presence of ofloxacin. The immunoblot analysis showed that the new proteins of 40 kDa and 30 kDa molecular masses were expressed on the outer envelope, when being exposed to antibiotics ceftazidime and ofloxacin, respectively. This finding is important, as the outer surface comes in contact with the immune system, and therefore may have a bearing on the outcome of the disease.

• Korean Journal of Veterinary Service
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• v.33 no.1
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• pp.23-27
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• 2010

This survey was performed to investigate the seroprevalence of antibodies to Brucella canis in dogs from public animal shelters and breeding kennels in Incheon. A total of 402 dogs selected randomly were tested serologically by using immunochromatographic antibody test kit. None of 289 dogs in public animal shelters were sero-positive and 10 (8.9%) of 113 dogs in breeding kennels were sero-positive. 5 (4.4%) strains of Brucella canis were isolated from 10 sero-positive dogs' blood. Antimicrobial susceptibility test was carried out by Disk diffusion method. They were susceptible to tetracyclines, quinolones, aminoglycosides and combination amoxicillin with clavulanic acid.

• Journal of Life Science
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• v.13 no.6
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• pp.943-949
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• 2003

New quinolone derivatives of 7-(cis- or trans-3-amino-4-mehtylthiomethylpyrrolidinyl) quinolone-3-carboxylic acids were synthesized by condensation of 7-halo substituted quinolone-3-carboxylic acids with cis- or trans-3-amino-4-mehtylthiomethylpyrrolidine. Some of these compounds showed broad spectra of antibacterial activities against Gram-positive and Gram-negative organisms except Pseudomonas aeruginosa, and exhibited much stronger activity against MRSA.

• Bulletin of the Korean Chemical Society
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• v.15 no.12
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• pp.1070-1079
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• 1994

Quantitative Structure-Activity Relationship (QSAR) studies are performed for the sets of 40 quinolones and 47 naphthyridines. Net charge, van der Waals volume, polarizability, and dipole moment are empolyed as theoretical descriptors(independent variables) to find the relationship between activity and physicochemical properties such as electrostatic effect, steric effect, and transferability. The results are analyzed by the regression and the factor analysis. It is found that for Gram-negative bacteria, the QSAR of quinolone and naphthyridine are substantially different: to describe the activity, the electrostatic effect is the most important for quinolone, and the steric effect and the transferability for naphthyridine.