In vitro and in vivo antibacterial evaluation of cadazolid, a new antibiotic for treatment of Clostridium difficile infections.

Abstract

Clostridium difficile is a leading cause of health care-associated diarrhea with significant morbidity and mortality, and new options for the treatment of C. difficile-associated diarrhea (CDAD) are needed. Cadazolid is a new oxazolidinone-type antibiotic that is currently in clinical development for treatment of CDAD. Here, we report the in vitro and in vivo antibacterial evaluation of cadazolid against C. difficile. Cadazolid showed potent in vitro activity against C. difficile with a MIC range of 0.125 to 0.5 μg/ml, including strains resistant to linezolid and fluoroquinolones. In time-kill kinetics experiments, cadazolid showed a bactericidal effect against C. difficile isolates, with >99.9% killing in 24 h, and was more bactericidal than vancomycin. In contrast to metronidazole and vancomycin, cadazolid strongly inhibited de novo toxin A and B formation in stationary-phase cultures of toxigenic C. difficile. Cadazolid also inhibited C. difficile spore formation substantially at growth-inhibitory concentrations. In the hamster and mouse models for CDAD, cadazolid was active, conferring full protection from diarrhea and death with a potency similar to that of vancomycin. These findings support further investigations of cadazolid for the treatment of CDAD.

• Authors: Hans H Locher, Peter Seiler, Xinhua Chen, Susanne Schroeder, Philippe Pfaff, Michel Enderlin, Axel Klenk, Elvire Fournier, Christian Hubschwerlen, Daniel Ritz, Ciaran P Kelly, Wolfgang Keck
• Journal: Antimicrobial agents and chemotherapy (Antimicrob Agents Chemother) Vol. 58 Issue 2 Pg. 892-900 ( 2014) ISSN: 1098-6596 [Electronic] United States
• PMID: 24277020 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)

Chemical References

• Acetamides
• Anti-Bacterial Agents
• Bacterial Proteins
• Bacterial Toxins
• Enterotoxins
• Fluoroquinolones
• Oxazolidinones
• tcdA protein, Clostridium difficile
• toxB protein, Clostridium difficile
• Metronidazole
• cadazolid
• Vancomycin
• Linezolid

Topics

• Acetamides (pharmacology)
• Animals
• Anti-Bacterial Agents (pharmacology)
• Bacterial Proteins (antagonists & inhibitors, biosynthesis)
• Bacterial Toxins (antagonists & inhibitors, biosynthesis)
• Clostridioides difficile (drug effects, growth & development, metabolism)
• Clostridium Infections (drug therapy, microbiology, mortality)
• Cricetinae
• Enterocolitis, Pseudomembranous (drug therapy, microbiology, mortality)
• Enterotoxins (antagonists & inhibitors, biosynthesis)
• Female
• Fluoroquinolones (pharmacology)
• Humans
• Linezolid
• Male
• Metronidazole (pharmacology)
• Mice
• Mice, Inbred C57BL
• Microbial Sensitivity Tests
• Oxazolidinones (pharmacology)
• Spores, Bacterial (drug effects, growth & development)
• Survival Analysis
• Vancomycin (pharmacology)