Whither triclosan?
by
Russell AD.
Welsh School of Pharmacy,
Cardiff University,
Cardiff CF10 3XF, UK. J Antimicrob Chemother. 2004 May;53(5):693-5. Epub 2004 Apr 8.
ABSTRACT
Triclosan has activity against many, but not all, types of
Gram-positive and Gram-negative bacteria. It is bacteriostatic at low
concentrations, but higher concentrations are bactericidal. Pseudomonas
aeruginosa is highly resistant, whereas methicillin-resistant
Staphylococcus aureus strains are inhibited over a range of
approximately 0.1-2 mg/L. Triclosan shows significant activity against
some mycobacteria, but is not sporicidal. Its growth-inhibitory
properties result from an inhibition of enoyl reductase, FabI.
Membrane-destabilizing effects are likely to be responsible for
bacterial inactivation by higher concentrations. Resistance can arise
from mutations in, and/or overproduction of, FabI, impermeability or
efflux. Whilst triclosan resistance in laboratory experiments may be
associated with changes in antibiotic susceptibility, comprehensive
environmental surveys have not demonstrated any association between
triclosan usage and antibiotic resistance. Triclosan has several
important uses, and the future aim must be to retain these applications
whilst eliminating the more frivolous and unnecessary ones.