• Journal of Life Science
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• v.17 no.3 s.83
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• pp.435-443
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• 2007

Antimicrobial susceptibility test of the 116 strains of Mycoplasma pneumoniae isolates were performed by a broth micro-dilution method against to moxifloxacin, levofloxacin, sparfloxacin, ofloxacin, ciprofloxacin, clarithromycin minocycline, erythromycin, josamycin, and tetracycline. The initial-minimum inhibitory concentration (I-MIC) was evaluated as the lowest concentration of antimicrobial agents that prevented a color change in the medium at that time when the drug-free growth control, about 7 days after incubation, and the final-minimum inhibitory concentration (F-MIC) was defined a color change about 14 days after incubation. The evaluation to the drug-resistant M. pneumoniae isolates were determined the $MIC{\pm}1.0$ ${\mu}g/ml$ of each antimicrobial agent. According to the I-MIC, single drug-resistant M. pneumoniae strains to ciprofloxacin, ofloxacin, clarithromycin and erythromycin were 79.3, 53.5, 10.3, and 7.8%, respectively. Two kinds of drug-resistant M. pneumoniae strains to ofloxacin and ciprofloxacin, or ciprofloxacin and clarithromycin were 42.2 and 9.5%. Three kinds of drug-resistant M. pneumoniae strains to erythromycin, ofloxacin, and ciprofloxacin, or ofloxacin, ciprofloxacin and clarithromycin were 6.9 and 6.0% . According to the F-MIC, single drug-resistant M. pneumoniae strains to tetracycline, ciprofloxacin, ofloxacin, minocycline,erythromycin, josamycin, clarithromycin and sparfloxacin were 91.4, 91.4, 91.4, 89.7, 68.1, 52.6, 28.5, and 11.2%, respectively. The incidence of two kinds of drug-resistant M. pneumoniae strains were from 20.7% to 91.4%, three kinds of drug-resistant M. pneumoniae strains were from 28.5% to 89.7%, four kinds of drug-resistant M. pneumoniae strains were 2.6%, five kinds of drug-resistant M. pneumoniae were from 2.6% to 21.6%, six kinds of drug-resistant M. pneumoniae strains were from 0.9% to 24.1%, seven kinds of drug-resistant M. pneumoniae strains were from 0.9% to 2.6%, and eight kinds of drug-resistant M. pneumoniae strains were 1.7%. These results suggest that sparfloxacin, moxifloxacin and levofloxacin might be promising antimicrobial agents for the treatment of M. pneumoniae infection in Korea. However, most strains of M. pneumoniae isolates were single or multi-resistance pattern to the other tested antimicrobial agents. Therefore, tetracycline, minocycline, erythromycin, clarithromycin, and second-generation quinolones are more carefully used to patients with M. pneumoniae infection in Korea.

• 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.2
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• pp.168-170
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• 2007

In this research 26 Shigella isolates were examined by PCR and direct nucleotide sequencing for genetic alterations in the quinolone-resistance determining regions (QRDRs). We tested for the presence of qnr genes by PCR in 91 strains, but no qnr genes were found. The results did show, however, some novel mutations at codon 83 of gyrA ($Ser{\rightarrow}Ile$) and codon 64 of parC ($Ala64{\rightarrow}Cys,\;Ala64{\rightarrow}Asp$), which were related to fluroquinolone resistance.

• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2008.04a
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• pp.19-21
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• 2008

The quinolone antibiotics Ciprofloxacin shows broad antimicrobial spectrum, heat stability, limited water solubility, and similar structure and size to disperse dyes. The object of this study is to develop the infection-resistant medical extile material by applying Ciprofloxacin to a series of polyester materials such as PET, PDO, PLA, and PGA. All the Ciprofloxacin compound polyester materials demonstrated the superior antimicrobial activity to the organisms S. aureus and E. coli.

• 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.

• YAKHAK HOEJI
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• v.40 no.4
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• pp.438-441
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• 1996

The therapeutic activity of LB20304a was examined on experimental respiratory tract infection (RTI) caused by Klebsiella pneumoniae DT-S in mice. A single oral dose of LB 20304a (1.2mg/mouse) showed a rapid bacteriocidal activity in lung tissue at 4,7 and 24h after administration of drug. The in vivo activity of LB20304a was comparable to that of ciprofloxacin against K. pneumoniae infection, although in vitro MIC of LB20304a was four-fold higher than that of ciprofloxacin.

• 대한임상약리학회:학술대회논문집
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• 1998.12a
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• pp.68-68
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• 1998

• Korean Journal of Veterinary Research
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• v.39 no.2
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• pp.365-369
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• 1999

A study on quinolone antibacterial, norfloxacin, was performed to apply for the control of bacterial diseases in eel (Anguilla japonica). Norfloxacin was proved excellent in antibacterial activity and sensitivity against fish bacterial pathogens when compared with the existing antibacterials and antibiotics. And any side effect was not observed during the period of indicated use. An outline of minimal inhibitory concentration was $0.03{\sim}0.1{\mu}g/ml$, $TLm_{48h}$ value was 3,500mg/l. The residual time of the day in fish body was less than 17 days and any pathological changes were not observed. The study has revealed that norfloxacin can be applied to treat some fish bacterial disease by the dosage of 100g/day/ton of fish body weight for about 3 days perorally. Further, norfloxacin may be used for the control of bacterial pathogens in eel.

• 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.

• Bulletin of the Korean Chemical Society
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• v.15 no.6
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• pp.442-448
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• 1994

Transition metals tested, $Cu^{2+}$, and $Ni^{2+}$, were found effective in the induction of the cytotoxicity of the quinolones tested, nalidixic acid, oxolinic acid, and pipemidic acid, against L1210 leukemia cells in vitro, whereas the alkaline earth metal, $Mg^{2+}$, was not. The differential effect of the metals on the quinolone cytotoxicity can be explained by their different mode of interaction with the quinolones. Our present difference spectroscopic titration data suggest that the transition metals can form DNA-intercalating agents, with the quinolones, which can cause the cytotoxicity.