Antimicrobial activity of clofazimine is not dependent on mycobacterial C-type phospholipases

J Antimicrob Chemother. 2004 Jun;53(6):971-4. doi: 10.1093/jac/dkh215. Epub 2004 Apr 29.

Abstract

We have used a phospholipase C (PLC)-deletion mutant (plcABC) of the H37Rv strain of Mycobacterium tuberculosis (MTB), as well as a plcA-insertion mutant of Mycobacterium smegmatis, to investigate the possible involvement of PLCs in clofazimine-mediated inhibition of mycobacterial K(+) transport and growth. Inactivation of the PLCs of MTB and insertion of the plcA gene into M. smegmatis resulted in a substantial reduction and increase in hydrolysis of phosphatidylcholine (PC), respectively. However, both the mutant and wild-type strains of MTB and M. smegmatis were equally sensitive to the inhibitory effects of clofazimine on K(+) uptake and growth. These observations demonstrate that the PLCs of MTB are not involved in the antimicrobial activity of clofazimine.

MeSH terms

  • Anti-Infective Agents / pharmacology*
  • Arachidonic Acid / metabolism
  • Clofazimine / pharmacology*
  • Cyclohexanones / pharmacology
  • Gene Deletion
  • Hydrolysis
  • Lipoprotein Lipase / antagonists & inhibitors
  • Mycobacterium smegmatis / drug effects
  • Mycobacterium smegmatis / enzymology
  • Mycobacterium smegmatis / genetics
  • Mycobacterium tuberculosis / drug effects*
  • Mycobacterium tuberculosis / enzymology*
  • Mycobacterium tuberculosis / genetics
  • Rubidium Radioisotopes
  • Type C Phospholipases / genetics
  • Type C Phospholipases / physiology*

Substances

  • Anti-Infective Agents
  • Cyclohexanones
  • Rubidium Radioisotopes
  • Arachidonic Acid
  • 1,6-bis(cyclohexyloximinocarbonyl)hexane
  • Clofazimine
  • Lipoprotein Lipase
  • Type C Phospholipases