Blog
About

3
views
0
recommends
+1 Recommend
0 collections
    0
    shares
      • Record: found
      • Abstract: found
      • Article: not found

      Quinolone efflux pumps play a central role in emergence of fluoroquinolone resistance in Streptococcus pneumoniae.

      Antimicrobial Agents and Chemotherapy

      Anti-Infective Agents, Animals, pharmacology, Carrier Proteins, metabolism, Drug Resistance, Bacterial, physiology, Fluoroquinolones, Mice, Microbial Sensitivity Tests, Models, Animal, Models, Biological, Pneumococcal Infections, drug therapy, microbiology, Quinolones, chemistry, Streptococcus pneumoniae, drug effects, enzymology, genetics

      Read this article at

      ScienceOpenPublisherPMC
      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          The preferential use of older antimicrobial agents is, in general, sound public health policy and is meant to maintain susceptibility to newer agents. In the case of fluoroquinolones, however, this strategy is flawed and may actually hasten the spread of Streptococcus pneumoniae strains resistant to newer members of the class. In a mouse thigh infection model, we were unable to isolate clones of pneumococci resistant to the newer fluoroquinolone levofloxacin at 2 x or 4 x the baseline MIC. An initial exposure in vivo to the older agent, ciprofloxacin, allowed straightforward selection of clones resistant to levofloxacin in a subsequent experiment. The original ciprofloxacin exposure generated clones without changes in the parC/E and gyrA/B quinolone target sites almost exclusively but did allow overexpression of a reserpine-responsive pump. While this caused only minimal change in the levofloxacin MIC (0.6 mg/liter to 0.8 mg/liter), it allowed a major change in the mutational frequency to resistance for levofloxacin (<1/10(8.5) to approximately 1/10(4.5)), which allowed levofloxacin-resistant clones to be isolated in a subsequent in vivo experiment. The reason underlying ciprofloxacin's propensity to select for pump-overexpressed clones is likely related to its hydrophilicity. To preserve the susceptibility of Streptococcus pneumoniae to newer members of the class of quinolones, use of ciprofloxacin for community-acquired respiratory infections should be minimized.

          Related collections

          Author and article information

          Journal
          16377702
          1346791
          10.1128/AAC.50.1.310-317.2006

          Comments

          Comment on this article