Analysis of Clostridium difficile biofilms: imaging and antimicrobial treatment

• Published in: Journal of antimicrobial chemotherapy 2018-01, Vol.73 (1), p.102-108
• Main Authors: James, Garth A, Chesnel, Laurent, Boegli, Laura, deLancey Pulcini, Elinor, Fisher, Steve, Stewart, Philip S
• Format: Article
• Language: English
• Subjects: Aminoglycosides - pharmacology; Anti-Bacterial Agents - pharmacology; Biofilms - drug effects; Biological Transport - physiology; Clostridioides difficile - drug effects; Clostridioides difficile - growth & development; Colony Count, Microbial; Fidaxomicin; Humans; Lipopeptides - pharmacology; Metronidazole - pharmacology; Microbial Sensitivity Tests; Microscopy, Electron, Scanning; Peptides, Cyclic - pharmacology; Spores, Bacterial - drug effects; Vancomycin - pharmacology
• ISSN: 0305-7453; 1460-2091
• DOI: 10.1093/jac/dkx353

Clostridium difficile, a spore-forming Gram-positive anaerobic bacillus, is the most common causative agent of healthcare-associated diarrhoea. Formation of biofilms may protect C. difficile against antibiotics, potentially leading to treatment failure. Furthermore, bacterial spores or vegetative cells may linger in biofilms in the gut causing C. difficile infection recurrence. In this study, we evaluated and compared the efficacy of four antibiotics (fidaxomicin, surotomycin, vancomycin and metronidazole) in penetrating C. difficile biofilms and killing vegetative cells. C. difficile biofilms grown initially for 48 or 72 h using the colony biofilm model were then treated with antibiotics at a concentration of 25 × MIC for 24 h. Vegetative cells and spores were enumerated. The effect of treatment on biofilm structure was studied by scanning electron microscopy (SEM). The ability of fidaxomicin and surotomycin to penetrate biofilms was studied using fluorescently tagged antibiotics. Both surotomycin and fidaxomicin were significantly more effective than vancomycin or metronidazole (P