In vitro activities of oral antimicrobial agents against penicillin-resistant Streptococcus pneumoniae: implications for outpatient treatment

South Med J. 1997 Jun;90(6):621-6. doi: 10.1097/00007611-199706000-00008.

Abstract

We tested 83 penicillin-intermediate (Peni) and 50 penicillin-resistant (Penr) isolates of Streptococcus pneumoniae against eight oral antimicrobials. Clarithromycin's MICs (minimal inhibitory concentration) were generally the same or one to two dilutions less than those of azithromycin. Seventy-two percent of Peni isolates were susceptible to clarithromycin and azithromycin, in contrast to 42% and 40%, respectively, of Penr isolates. Cefuroxime activity exceeded that of cefprozil, which exceeded that of cefaclor, in Peni isolates. For all three cephalosporins, MICs of 90% of isolates tested were > or = 3 dilutions higher for Penr isolates than for Peni isolates. Percentages of Peni isolates susceptible to clindamycin and tetracycline were 92% and 83%, respectively, and 78% and 82% for Penr. Only 49% of Peni isolates and 4% of Penr isolates were susceptible to trimethoprim-sulfamethoxazole. Azithromycin, clarithromycin, cefuroxime, cefprozil, clindamycin, and tetracycline may be useful in treating infections caused by Peni S pneumoniae, but Penr isolates are frequently resistant to both old and newer agents.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Administration, Oral
  • Adult
  • Ambulatory Care
  • Anti-Bacterial Agents / administration & dosage
  • Anti-Bacterial Agents / therapeutic use*
  • Azithromycin / administration & dosage
  • Azithromycin / therapeutic use
  • Cefaclor / administration & dosage
  • Cefaclor / therapeutic use
  • Cefprozil
  • Cefuroxime / administration & dosage
  • Cefuroxime / therapeutic use
  • Cephalosporins / administration & dosage
  • Cephalosporins / therapeutic use
  • Child
  • Clarithromycin / administration & dosage
  • Clarithromycin / therapeutic use
  • Clindamycin / administration & dosage
  • Clindamycin / therapeutic use
  • Culture Media
  • Humans
  • Penicillin Resistance*
  • Pneumococcal Infections / drug therapy
  • Streptococcus pneumoniae / drug effects*
  • Tetracycline / administration & dosage
  • Tetracycline / therapeutic use
  • Trimethoprim, Sulfamethoxazole Drug Combination / administration & dosage
  • Trimethoprim, Sulfamethoxazole Drug Combination / therapeutic use

Substances

  • Anti-Bacterial Agents
  • Cephalosporins
  • Culture Media
  • Clindamycin
  • Cefaclor
  • Trimethoprim, Sulfamethoxazole Drug Combination
  • Azithromycin
  • Tetracycline
  • Clarithromycin
  • Cefuroxime