In vitro activities of rifamycin derivatives ABI-1648 (Rifalazil, KRM-1648), ABI-1657, and ABI-1131 against Chlamydia trachomatis and recent clinical isolates of Chlamydia pneumoniae

Antimicrob Agents Chemother. 2003 Mar;47(3):1135-6. doi: 10.1128/AAC.47.3.1135-1136.2003.

Abstract

ABI-1648 (rifalazil) is a semisynthetic rifamycin with potent bactericidal activity against intracellular respiratory bacteria, including Mycobacterium tuberculosis, and a long half-life (approximately 60 h) and thus can be administered once weekly. We therefore tested the in vitro activities of ABI-1648, its derivatives ABI-1657 and ABI-1131, azithromycin, and levofloxacin against 10 strains of Chlamydia trachomatis and 10 recent clinical isolates of Chlamydia pneumoniae. The MICs at which 90% of the isolates were inhibited and the minimal bactericidal concentration at which 90% of the isolates were killed for ABI-1648, ABI-1657, and ABI-1131 were 0.0025 micro g/ml for C. trachomatis and 0.00125 to 0.0025 micro g/ml for C. pneumoniae. ABI-1648, ABI-1657, and ABI-1131 were 10- to 1,000-fold more active than azithromycin and levofloxacin.

MeSH terms

  • Anti-Bacterial Agents / pharmacology
  • Anti-Infective Agents / pharmacology
  • Antibiotics, Antitubercular / pharmacology*
  • Azithromycin / pharmacology
  • Chlamydia Infections / microbiology
  • Chlamydia trachomatis / drug effects*
  • Chlamydophila pneumoniae / drug effects*
  • Humans
  • Levofloxacin
  • Microbial Sensitivity Tests
  • Ofloxacin / pharmacology
  • Rifamycins / pharmacology*

Substances

  • ABI 1131
  • ABI 1657
  • Anti-Bacterial Agents
  • Anti-Infective Agents
  • Antibiotics, Antitubercular
  • Rifamycins
  • KRM 1648
  • Levofloxacin
  • Azithromycin
  • Ofloxacin