Background: Candida auris is an emerging multidrug-resistant fungus associated with catheter-related bloodstream infections (CRBSI). In-vitro efficacy of chlorhexidine (CHX) and CHX/silver sulfadiazine-impregnated (CHX-S) antimicrobial central venous catheters (CVCs) against C. auris was investigated.

Material and methods: Minimum inhibitory (MIC) and bactericidal (MBC) CHX concentrations were determined against nineteen 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-days, and to assess intraluminal efficacy CHX-S2 CVCs were pre-conditioned with saline-lock for 6-days, followed by 24-hour C. auris inoculation and microbial adherence determination on impregnated and non-impregnated CVCs.

Results: CHX inhibited all C. auris isolates with MIC and MBC range of 8-128 μg/mL. C. auris adherence was reduced on CHX-S1 and CHX-S2 extraluminally by 100% on day-1, 86.96%-100% on day-7, and intraluminally on CHX-S2 by 56.86%-90.52% on day-7.

Discussion: CHX and CHX-S CVCs performance against C. auris observed in this study is consistent with antimicrobial benefits observed in prior pre-clinical 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.

Gupta N, Haughton S, Kemper S, Koehler M, Antoon R, Edwards CG, Bardin A. The antimicrobial effectiveness of chlorhexidine and chlorhexidine-silver sulfadiazine impregnated central venous catheters against the emerging fungal pathogen Candida auris. Am J Infect Control. 2024 Jun 27:S0196-6553(24)00576-5. doi: 10.1016/j.ajic.2024.06.015. Epub ahead of print. PMID: 38944155.