Research of the effect of persisters in Candida albicans biofilm on antifungal therapy using a Caenorhabditis elegans infection model

Abstract

Objective To illuminate the effect of persisters on antifungal therapy by infecting Caenorhabditis elegans as a live-animal model with Candida albicans isolates of different persister levels, treating them with amphotericin B and comparing the survival rate. Methods Glp-4 (bn2ts); sek-1 (km4) worms were synchronized and grown to sterile to L4-stage, put on different Candida albicans strains lawns separately for 2 h. Dispensed 15-20 worms per well of the 96-well plate, and added serial dilutions of amphotericin B for each strain group. Wells filled without any amphotericin B were used as negative controls intra-group. Incubated the plate at 25C for 5 days, counted the survival rate of each well. Results Compared with negative controls, survival rate of drug wells in each group increased. In the same drug concentration, the increase for high-persister group was significantly lower than that for low-persister group (P＜0.01). Conclusion Caenorhabditis elegans provides a model for the study of persisters and antifungal pharmacodynamics.The drug tolerance of persisters may be a critical component responsible for antifungal drug failure and relapsing infections. Key words: Candida albicans; Biofilm; Persisters; Antifungal; Caenorhabditis elegans