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Using the Overlay Assay to Qualitatively Measure Bacterial Production of and Sensitivity to Pneumococcal Bacteriocins
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Comparative activities of beta-lactam antibiotics and quinolones for invasive Streptococcus pneumoniae isolates

Serkan Oncü1, Metin Punar, Haluk Eraksoy

  • 1Departments of Infectious Diseases and Clinical Microbiology, Adnan Menderes University Faculty of Medicine, Aydin, Turkey. serkanoncu@hotmail.com

Chemotherapy
|June 24, 2004
PubMed
Abstract

Insights

New quinolones like gemifloxacin and trovafloxacin show high activity against Streptococcus pneumoniae. These antibiotics hold promise for treating invasive pneumococcal infections, even those resistant to penicillin.

Area of Science:

  • Microbiology
  • Infectious Diseases
  • Pharmacology

Background:

  • Streptococcus pneumoniae causes severe pneumonia and meningitis.
  • Invasive pneumococcal infections lead to significant mortality.
  • Antibiotic resistance in S. pneumoniae is a growing concern.

Purpose of the Study:

  • To evaluate the in vitro activity of five quinolones against invasive pneumococcal isolates.
  • To compare the efficacy of new quinolones with existing antibiotics.
  • To assess the impact of penicillin resistance on quinolone effectiveness.

Main Methods:

  • Broth microdilution method used to determine Minimum Inhibitory Concentrations (MICs).
  • Tested antibiotics included penicillin G, cefuroxime, azithromycin, clarithromycin, trimethoprim-sulfamethoxazole (SXT), ciprofloxacin, ofloxacin, levofloxacin, trovafloxacin, and gemifloxacin.
  • Eighty-five invasive pneumococcal isolates were analyzed.

Main Results:

  • High resistance rates observed for penicillin (46%) and SXT (46%).
  • Gemifloxacin and trovafloxacin demonstrated the highest in vitro activity among the tested quinolones.
  • Penicillin resistance did not affect the susceptibility patterns to the new quinolones.

Conclusions:

  • New quinolones exhibit potent activity against both penicillin-susceptible and penicillin-resistant Streptococcus pneumoniae.
  • Gemifloxacin and trovafloxacin represent promising therapeutic options for invasive pneumococcal diseases.
  • Further investigation into novel quinolones is warranted for combating antibiotic resistance.

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