The antimicrobial effectiveness of chlorhexidine and chlorhexidinesilver sulfadiazine-impregnated central venous catheters against the emerging fungal pathogen Candida auris

Background: Candida auris is an emerging multidrug-resistant fungus associated with catheter-related bloodstream infections. In vitro efficacy of chlorhexidine (CHX) and CHX-silver sulfadiazine-impregnated (CHX-S) antimicrobial central venous catheters (CVCs) against C auris was investigated. Methods: Minimum inhibitory and bactericidal CHX concentrations were determined against 19 C auris isolates. To assess extraluminal efficacy, segments from CVCs impregnated externally (CHX-S1) and both externally and internally (CHX-S2) were plasma-conditioned for 1- and 6-day, and to assess intraluminal efficacy, CHX-S2 CVCs were preconditioned with saline-lock for 6 days, followed by 24-hour C auris inoculation and microbial adherence determination on impregnated and nonimpregnated CVCs. Results: CHX inhibited all C auris isolates with minimum inhibitory and bactericidal concentrations range of 8 to 128 mu g/mL. C auris adherence was reduced on CHX-S1 and CHX-S2 extraluminally by 100% on day 1, 86.96% to 100% on day 7, and intraluminally on CHX-S2 by 56.86% to 90.52% on day 7. Discussion: CHX and CHX-S CVC performance against C auris observed in this study is consistent with antimicrobial benefits observed in prior preclinical and randomized controlled clinical studies. Conclusions: CHX showed strong inhibitory and cidal effects on C auris. CHX-S CVCs proved highly efficacious against this pathogen under in vitro conditions. Additional studies, however, are required to confirm clinical benefit. (c) 2024 The Author(s). Published by Elsevier Inc. on behalf of Association for Professionals in Infection Control and Epidemiology, Inc. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).