In Vitro Antimicrobial Activity of Taurolidine Against Isolates Associated with Catheter-Related Bloodstream Infections

Background: Catheter-related bloodstream infections are common in patients receiving hemodialysis through a central venous catheter. Taurolidine, a novel broad-spectrum antimicrobial catheter lock solution, is FDA-approved in combination with heparin for reducing the incidence of such infections. Methods: In vitro activity of taurolidine was assessed against 442 bacterial and 50 yeast clinical bloodstream infection isolates selected from the SENTRY Antimicrobial Surveillance Program and tested according to the Clinical and Laboratory Standards Institute methodology. Multidrug-resistant species and phenotypes were included. Results: Taurolidine was highly active against all isolates, with MIC50/MIC90 values of ≤1024/1024 μg/mL for most species. The highest MICs observed were among isolates of Mycobacterium avium complex and Burkholderia cepacia complex (MIC90, 2048 μg/mL) and Candida albicans (MIC90, 4096 μg/mL). All isolates were inhibited by 13,500 μg/mL of taurolidine, the concentration of the commercially available product. Conclusions: Taurolidine activity was very similar among Gram-positive, Gram-negative, and yeast clinical isolates, with the activity of taurolidine being unaffected by phenotypic resistance to other antimicrobials. Taken together with clinical efficacy data from clinical trials, this provides a theoretical basis for the idea that taurolidine-based lock solutions may be able to reduce the risk of catheter-related bloodstream infections from a wide variety of pathogens and resistance phenotypes.