This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrowReprints and Permissions
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Ito, T.
Right arrow Articles by Nishino, T.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Ito, T.
Right arrow Articles by Nishino, T.

 Previous Article  |  Next Article 

Antimicrobial Agents and Chemotherapy, Jul 1995, 1522-1525, Vol 39, No. 7
Copyright © 1995 by the American Society for Microbiology. All rights reserved.

Improved bactericidal activity of Q-35 against quinolone-resistant staphylococci

T Ito, M Matsumoto and T Nishino
Fuji-Gotemba Research Laboratories, Chugai Pharmaceutical Co., Ltd., Shizuoka, Japan.

The bactericidal effects of Q-35, sparfloxacin, tosufloxacin, and ofloxacin on 18 strains of methicillin-resistant Staphylococcus aureus (MRSA) and 3 strains of Staphylococcus epidermidis were studied by a viable-count method. Staphylococci as used in this study were clearly divided into two groups with respect to their susceptibilities to sparfloxacin. MICs of Q-35 and tosufloxacin were 0.05 to 0.78 microgram/ml for sparfloxacin-susceptible strains (MICs, 0.05 to 0.2 microgram/ml) and 1.56 to 12.5 micrograms/ml for sparfloxacin-resistant strains (6.25 to 25 micrograms/ml). All the sparfloxacin-resistant strains of MRSA tested contained the gyrA mutation at codon 84. Time- kill studies showed that Q-35 decreased the viable counts from approximately 10(7) CFU/ml to 10(3) to 10(5) CFU/ml within 3 h at concentrations greater than the MICs against both sparfloxacin- susceptible and -resistant strains. In contrast, sparfloxacin, tosufloxacin, and ofloxacin produced bacteriostatic effects at 3 h after exposure against sparfloxacin-resistant strains at concentrations which were greater than the respective MICs, whereas these quinolones were bactericidal against sparfloxacin-susceptible strains. The rapid bactericidal activities of Q-35 against sparfloxacin-resistant MRSA were reduced when the methoxy group of Q-35 at the 8 position was substituted with fluorine or hydrogen. Thus, our data suggest that the introduction of a methoxy group into the 8 position of quinolones contributes to the bactericidal activities of fluoroquinolones against quinolone-resistant staphylococci.


This article has been cited by other articles:

  • German, N., Malik, M., Rosen, J. D., Drlica, K., Kerns, R. J. (2008). Use of Gyrase Resistance Mutants To Guide Selection of 8-Methoxy-Quinazoline-2,4-Diones. Antimicrob. Agents Chemother. 52: 3915-3921 [Abstract] [Full Text]  
  • Allen, G. P., Kaatz, G. W., Rybak, M. J. (2003). Activities of Mutant Prevention Concentration-Targeted Moxifloxacin and Levofloxacin against Streptococcus pneumoniae in an In Vitro Pharmacodynamic Model. Antimicrob. Agents Chemother. 47: 2606-2614 [Abstract] [Full Text]  
  • Kishii, R., Takei, M., Fukuda, H., Hayashi, K., Hosaka, M. (2003). Contribution of the 8-Methoxy Group to the Activity of Gatifloxacin against Type II Topoisomerases of Streptococcus pneumoniae. Antimicrob. Agents Chemother. 47: 77-81 [Abstract] [Full Text]  
  • Takei, M., Fukuda, H., Kishii, R., Kadowaki, Y., Atobe, Y., Hosaka, M. (2002). Contribution of the C-8-Methoxy Group of Gatifloxacin to Inhibition of Type II Topoisomerases of Staphylococcus aureus. Antimicrob. Agents Chemother. 46: 3337-3338 [Full Text]  
  • Lu, T., Zhao, X., Li, X., Drlica-Wagner, A., Wang, J.-Y., Domagala, J., Drlica, K. (2001). Enhancement of Fluoroquinolone Activity by C-8 Halogen and Methoxy Moieties: Action against a Gyrase Resistance Mutant of Mycobacterium smegmatis and a Gyrase-Topoisomerase IV Double Mutant of Staphylococcus aureus. Antimicrob. Agents Chemother. 45: 2703-2709 [Abstract] [Full Text]  
  • Schmitz, F.-J., Boos, M., Mayer, S., Hafner, D., Jagusch, H., Verhoef, J., Fluit, A. C. (2001). Propensity of Fluoroquinolones with Different Moieties at Position 8 to Cause Resistance Development in Clinical Isolates of Streptococcus pneumoniae. Antimicrob. Agents Chemother. 45: 2666-2667 [Full Text]  
  • Fukuda, H., Kishii, R., Takei, M., Hosaka, M. (2001). Contributions of the 8-Methoxy Group of Gatifloxacin to Resistance Selectivity, Target Preference, and Antibacterial Activity against Streptococcus pneumoniae. Antimicrob. Agents Chemother. 45: 1649-1653 [Abstract] [Full Text]  
  • Lu, T., Zhao, X., Drlica, K. (1999). Gatifloxacin Activity against Quinolone-Resistant Gyrase: Allele-Specific Enhancement of Bacteriostatic and Bactericidal Activities by the C-8-Methoxy Group. Antimicrob. Agents Chemother. 43: 2969-2974 [Abstract] [Full Text]  
  • Zhao, B. Y., Pine, R., Domagala, J., Drlica, K. (1999). Fluoroquinolone Action against Clinical Isolates of Mycobacterium tuberculosis: Effects of a C-8 Methoxyl Group on Survival in Liquid Media and in Human Macrophages. Antimicrob. Agents Chemother. 43: 661-666 [Abstract] [Full Text]  
  • Dong, Y., Xu, C., Zhao, X., Domagala, J., Drlica, K. (1998). Fluoroquinolone Action against Mycobacteria: Effects of C-8 Substituents on Growth, Survival, and Resistance. Antimicrob. Agents Chemother. 42: 2978-2984 [Abstract] [Full Text]  
  • Zhao, X., Wang, J.-Y., Xu, C., Dong, Y., Zhou, J., Domagala, J., Drlica, K. (1998). Killing of Staphylococcus aureus by C-8-Methoxy Fluoroquinolones. Antimicrob. Agents Chemother. 42: 956-958 [Abstract] [Full Text]  
  • Zhao, X., Xu, C., Domagala, J., Drlica, K. (1997). DNA topoisomerase targets of the fluoroquinolones: A strategy for avoiding bacterial resistance. Proc. Natl. Acad. Sci. USA 94: 13991-13996 [Abstract] [Full Text]  


Copyright © 2009 by the American Society for Microbiology.   For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»