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In vitro activities of cefepime versus cefotaxime and ceftriaxone against penicillin-resistant Streptococcus

K B Waites1, B M Gray, E Swiatlo

  • 1Department of Pathology, WP 230, 618 S. 18th Street, University of Alabama at Birmingham, Birmingham, AL 35233-7331, USA. Waites@wp.path .uab.edu

International Journal of Antimicrobial Agents
|July 10, 2008
PubMed

Insights

The Etest accurately determined in vitro susceptibilities of penicillin-intermediate and resistant Streptococcus pneumoniae to cefepime, cefotaxime, and ceftriaxone. This method is practical for clinical diagnostic laboratories.

Area of Science:

  • Microbiology
  • Infectious Diseases
  • Clinical Pharmacy

Background:

  • Penicillin-intermediate and resistant Streptococcus pneumoniae pose a significant challenge in clinical settings.
  • Accurate susceptibility testing is crucial for guiding effective antibiotic therapy.

Purpose of the Study:

  • To evaluate the in vitro activity of cefepime, cefotaxime, and ceftriaxone against clinical isolates of Streptococcus pneumoniae.
  • To assess the utility of the Etest method for determining these susceptibilities.

Main Methods:

  • The Etest method was employed to determine the minimum inhibitory concentrations (MICs) of cefepime, cefotaxime, and ceftriaxone.
  • One hundred forty-four unique clinical isolates of penicillin-intermediate and resistant Streptococcus pneumoniae were tested.

Main Results:

  • MIC ranges for cefepime were 0.12-8 µg/ml, and for cefotaxime and ceftriaxone were 0.06-16 µg/ml.
  • MICs for 50% of isolates were 1 µg/ml for all three agents.
  • MICs for 90% of isolates were 2 µg/ml for cefotaxime and ceftriaxone, and 4 µg/ml for cefepime.

Conclusions:

  • The Etest is a practical and reliable method for determining in vitro susceptibilities of Streptococcus pneumoniae to cefepime and other cephalosporins.
  • These findings support the use of cefepime, cefotaxime, and ceftriaxone in treating infections caused by susceptible S. pneumoniae strains.

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