Journal Article

Anti-staphylococcal activity and mode of action of clofazimine

Brunello Oliva, Alexander John O’Neill, Keith Miller, William Stubbings and Ian Chopra

in Journal of Antimicrobial Chemotherapy

Published on behalf of British Society for Antimicrobial Chemotherapy

Volume 53, issue 3, pages 435-440
Published in print March 2004 | ISSN: 0305-7453
Published online March 2004 | e-ISSN: 1460-2091 | DOI:
Anti-staphylococcal activity and mode of action of clofazimine

Show Summary Details


Objectives: Infections caused by Staphylococcus aureus might be treated with agents whose primary indications are for other infections. Clofazimine, an established anti-mycobacterial drug, could be such a candidate. However, the anti-staphylococcal properties of clofazimine have not been fully described and its mode of action, possibly involving inhibition of both RNA polymerase and a membrane-located target, has not been explored in detail. We have now conducted experiments to address these issues.

Methods: Using established procedures, we examined the activity of clofazimine against a range of clinical isolates of S. aureus and determined whether it was bactericidal, exhibited a post-antibiotic effect (PAE), or interacted synergically with other agents. The potential for emergence of clofazimine-resistant mutants was also examined. Mode of action studies involved macromolecular synthesis assays, cross-screening against rifampicin-resistant mutants, susceptibility of RNA polymerase to clofazimine in vitro and several methods to detect drug-induced membrane damage.

Results: Clofazimine demonstrated good anti-staphylococcal activity encompassing MSSA, MRSA and GISA. It was bactericidal and resistant mutants could not be isolated. Clofazimine did not exhibit a PAE and failed to act synergically with other drugs. No evidence for specific inhibition of RNA polymerase was obtained. Clofazimine caused non-specific inhibition of DNA, RNA and protein synthesis, consistent with membrane-damaging activity that was detected in three independent assays for membrane disrupting agents.

Conclusions: Clofazimine is a potent anti-staphylococcal agent. It appears to be a membrane-disrupting agent and does not inhibit RNA polymerase.

Keywords: Keywords: Staphylococcus aureus, mechanisms of antibiotic action, membrane-disrupting agent

Journal Article.  3914 words.  Illustrated.

Subjects: Medical Oncology ; Critical Care

Full text: subscription required

How to subscribe Recommend to my Librarian

Users without a subscription are not able to see the full content. Please, subscribe or login to access all content.