Literature-Based Evaluation of the Potential Risks Associated with Impregnation of Medical Devices and Implants with Triclosan

Abstract

Background: This report is a review of the published literature for studies of triclosan that address mechanism of action, efficacy on skin and in the oral cavity, and the potential for development of resistance. Methods: Triclosan citations from the past three decades were searched using Medline and other search engines. The techniques used in these studies included in vitro antimicrobial sensitivity, molecular genetics, and enzyme and membrane biochemistry. Oral cavity efficacy and resistance studies were conducted in human volunteers in trials lasting up to 7 months. Efficacy on skin was reported in clinical trials lasting up to 12 months. Results: The minimal inhibitory concentration of triclosan against Staphylococcus aureus and Escherichia coli is reported to be 0.1 and 5.0 μg/mL, respectively. Triclosan acts by blocking enoyl acyl carrier protein reductase, an enzyme essential for fatty acid biosynthesis. Its biocidal activity involves a plethora of nonspecific perturbations of cellular structural elements, including the cell membrane. In the oral cavity, triclosan use was associated with significant reductions in recoverable flora; there was no evidence of resistance or emergence of opportunistic pathogens. On skin, in a neonatal intensive care unit, triclosan use was associated with a significant reduction in methicillin-resistant S. aureus (MRSA) infections, a diminished need for antibiotics, and a decreased incidence of nosocomial infections. Conclusion: There is currently no evidence that long-term application of triclosan products to the skin or oral cavity selects for triclosan-resistant populations. Given the short-term nature of suture use, it is highly unlikely that such use would do other than reduce the risks of postoperative infection.