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In vitro activity of grepafloxacin and 25 other antimicrobial agents against Streptococcus pneumoniae: correlation

C Thornsberry1, P T Ogilvie, H P Holley

  • 1MRL Pharmaceutical Services, Brentwood, Tennessee 37027, USA.

Clinical Therapeutics
|January 23, 1999
PubMed

Insights

Penicillin resistance in Streptococcus pneumoniae strains correlates with resistance to many antibiotics, but not fluoroquinolones, rifampin, or vancomycin. This guides empiric therapy selection for pneumococcal infections.

Area of Science:

  • Microbiology
  • Infectious Diseases
  • Pharmacology

Background:

  • Streptococcus pneumoniae is a leading cause of bacterial infections.
  • Antimicrobial resistance in S. pneumoniae poses a significant public health challenge.
  • Understanding resistance patterns is crucial for effective treatment.

Purpose of the Study:

  • To evaluate the in vitro susceptibility of S. pneumoniae strains to various antimicrobial agents.
  • To determine the correlation between penicillin resistance and resistance to other drug classes.
  • To inform empiric therapy choices for pneumococcal infections.

Main Methods:

  • Testing susceptibility of U.S. S. pneumoniae isolates (susceptible, intermediate, high penicillin resistance) to 26 antimicrobial agents.
  • Classifying agents into penicillins, cephalosporins, macrolides, fluoroquinolones, etc.
  • Analyzing correlations between penicillin resistance and resistance to other agents.

Main Results:

  • Penicillin and macrolide activities were similar; cephalosporin and fluoroquinolone activities varied.
  • Fluoroquinolone activity order: grepafloxacin > sparfloxacin > levofloxacin > ciprofloxacin > ofloxacin.
  • Penicillin resistance correlated with resistance to penicillins, cephalosporins, macrolides, clindamycin, tetracycline, and trimethoprim-sulfamethoxazole.

Conclusions:

  • Penicillin resistance in S. pneumoniae is linked to resistance to several key antibiotic classes.
  • Resistance to fluoroquinolones, rifampin, and vancomycin did not correlate with penicillin resistance.
  • Findings aid clinicians in selecting appropriate empiric treatment for S. pneumoniae infections.

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