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Antimicrobial activity and spectrum of sparfloxacin tested against erythromycin-resistant Streptococcus pneumoniae

M S Barrett1, R N Jones

  • 1Department of Pathology, University of Iowa College of Medicine, Iowa City, USA.

Diagnostic Microbiology and Infectious Disease
|February 1, 1996
PubMed

Insights

Sparfloxacin shows excellent activity against penicillin-resistant Streptococcus pneumoniae, demonstrating no cross-resistance with macrolides. This novel fluoroquinolone offers a promising alternative for treating infections caused by multi-drug resistant bacteria.

Area of Science:

  • Microbiology
  • Infectious Diseases
  • Pharmacology

Background:

  • Increasing prevalence of penicillin-resistant Streptococcus pneumoniae necessitates novel antimicrobial agents.
  • Cross-resistance to existing antibiotics, including macrolides, is a significant clinical challenge.
  • Erythromycin-resistant S. pneumoniae strains often exhibit multi-drug resistance, including to beta-lactams.

Purpose of the Study:

  • To evaluate the in vitro antimicrobial activity of sparfloxacin against erythromycin-resistant Streptococcus pneumoniae.
  • To compare sparfloxacin's efficacy with other antimicrobial agents against these resistant strains.
  • To investigate potential cross-resistance between macrolides/azalides and sparfloxacin.

Main Methods:

  • Etest susceptibility testing was performed on 50 strains of erythromycin-resistant S. pneumoniae.
  • Mueller-Hinton agar supplemented with 5% sheep blood was used for inoculation.
  • Sparfloxacin was compared against six other antimicrobial compounds.

Main Results:

  • No cross-resistance was observed between macrolides/azalides and sparfloxacin; all strains were susceptible to sparfloxacin (< or = 1.0 μg/ml).
  • Sparfloxacin exhibited potent activity (MIC90, 1 μg/ml), being four-fold more active than ciprofloxacin and ofloxacin (MIC90, 4 μg/ml).
  • Extensive cross-resistance was confirmed between erythromycin, clarithromycin (94%), and azithromycin (100%).

Conclusions:

  • Sparfloxacin demonstrates excellent in vitro activity against erythromycin-resistant Streptococcus pneumoniae.
  • The compound shows significant potential as a therapeutic option for infections caused by multi-resistant S. pneumoniae strains.
  • Further in vivo studies are recommended to confirm sparfloxacin's efficacy against these challenging pathogens.

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