Comparative Efficacies of Antimicrobial Catheter Lock Solutions for Fungal Biofilm Eradication in an in Vitro Model of Catheter-Related Fungemia.

Joel Rosenblatt,Nylev Vargas-Cruz,Anne-Marie Chaftari,Ruth Reitzel,Issam Raad,Ray Hachem

doi:10.3390/jof3010007

Abstract

Fungal catheter-related bloodstream infections (CRBSIs)—primarily due to Candida species—account for over 12% of all CRBSIs, and have been progressively increasing in prevalence. They present significant health and economic burdens, and high mortality rates. Antimicrobial catheter lock solutions are an important prophylactic option for preventing fungal CRBSIs. In this study, we compared the effectiveness of two FDA-approved catheter lock solutions (heparin and saline) and three experimental antimicrobial catheter lock solutions—30% citrate, taurolidine-citrate-heparin (TCH), and nitroglycerin-citrate-ethanol (NiCE)—in an in vitro model of catheters colonized by fungi. The fungi tested were five different strains of Candida clinical isolates from cancer patients who contracted CRBSIs. Time-to-biofilm-eradication was assessed in the model with 15, 30, and 60 min exposures to the lock solutions. Only the NiCE lock solution was able to fully eradicate all fungal biofilms within 60 min. Neither 30% citrate nor TCH was able to fully eradicate any of the Candida biofilms in this time frame. The NiCE lock solution was significantly superior to TCH in eradicating biofilms of five different Candida species (p = 0.002 for all).

Highlights

Central line associated bloodstream infections (CLABSIs) are a significant public health problem in the US reportedly affecting 250,000 patients annually, causing approximately 30,000 mortalities, and having an associated economic burden estimated to be $45,000 per patient [1,2]
In the 1990s, the NNIS (National Nosocomial Infection Surveillance System) reported that 8% of CLABSIs in the US were of fungal derivation [7]
We report results from an in vitro study in a well-established biofilm eradication model [25] for microbial colonization of catheter surfaces that comparatively assessed the potency of these three non-antifungal antimicrobial lock solutions for eradicating biofilms formed on catheter surfaces by Candida species

Summary

Introduction

Central line associated bloodstream infections (CLABSIs) are a significant public health problem in the US reportedly affecting 250,000 patients annually, causing approximately 30,000 mortalities, and having an associated economic burden estimated to be $45,000 per patient [1,2]. Precautionary procedural bundles include rigorous hand hygiene, the use of full-length sterile drapes, insertion-site skin antisepsis with chlorhexidine, and regular assessment of whether catheter removal is warranted. CLABSIs, those that do occur are increasingly luminally-sourced, and the catheter lumen is implicated as the source of CLABSI in as much as 90% [5,6] of all CLABSIs. In parallel, there has been a shift from a predominance of Gram-positive CLABSIs to increasing proportions of Gram-negative and fungal CLABSIs. In the 1990s, the NNIS (National Nosocomial Infection Surveillance System) reported that 8% of CLABSIs in the US were of fungal derivation (primarily Candida albicans, which caused 62.5% of candidemias) [7].

Methods

Results

Discussion

Conclusion