Antimicrobial and Antibiofilm Efficacy of Triclosan and DispersinB Combination

Objectives: The objectives of this study were to examine: (i) synergy of the combination of triclosan and DispersinB (DspB); (ii) in vitro efficacy and durability of triclosan + DspB-coated vascular catheters; and (iii) in vivo efficacy of triclosan + DspB-coated catheters compared with chlorhexidine-silver sulfadiazine (CH-SS)-coated and uncoated (control) vascular catheters in preventing colonization by Staphylococcus aureus.

Methods: We investigated the potential synergistic antimicrobial and antibiofilm activity of triclosan and DspB by biofilm assays. The in vitro antimicrobial efficacy of triclosan + DspB-coated catheters was determined by microbial colonization assays. Antimicrobial durability of the coated catheters was tested by soaking segments in bovine serum for 7 days and determining antimicrobial activity, and by a serial plate transfer method. The in vivo efficacy of triclosan + DspB-coated catheters compared with CH-SS-coated and uncoated catheters was assessed by subcutaneous implantation of segments in a rabbit model of S. aureus infection.

Results: The combination of triclosan and DspB showed synergistic antimicrobial and antibiofilm activity against S. aureus, Staphylococcus epidermidis and Escherichia coli, significantly reduced bacterial colonization (P < 0.05) and generally demonstrated a prolonged superior antimicrobial activity against clinical pathogens compared with CH-SS-coated catheters. Triclosan + DspB-coated and CH-SS-coated catheters exhibited equal in vivo efficacy (P <or= 0.05) in reducing colonization by S. aureus compared with uncoated catheters.

Conclusions: Catheters coated with the triclosan + DspB combination showed synergistic, broad-spectrum and durable antimicrobial activity. Furthermore, the in vivo efficacy of catheters coated with this unique antimicrobial/antibiofilm composition prompts clinical evaluation of such an innovative approach.