Effects of nanosecond pulsed electric fields (nsPEFs) on the human fungal pathogen Candida albicans: an in vitro study

Abstract Candida albicans is the leading human fungal pathogen that causes many life-threatening infections. Notably, the current clinical trial data indicate that Candida species shows the emerging resistance to anti-fungal drugs. The aim of this study was to evaluate the antifungal effects of nanosecond pulsed electric fields (nsPEFs) as a novel drug-free strategy in vitro . In this study, we investigated the inactivation and permeabilization effects of C. albicans under different nsPEFs exposure conditions (100 pulses, 100 ns in duration, intensities of 20, 40 kV cm −1 ). Cell death was studied by annexin-V and propidium iodide staining. The changes of intracellular Ca 2+ concentration after nsPEFs treatment were observed using Fluo-4 AM. Results show that C. albicans cells and biofilms were both obviously inhibited and destroyed after nsPEFs treatment. Furthermore, C. albicans cells were significantly permeabilized after nsPEFs treatment. Additionally, nsPEFs exposure led to a large amount of DNA and protein leakage. Importantly, nsPEFs induced a field strength-dependent apoptosis in C. albicans cells. Further experiments revealed that Ca 2+ involved in nsPEFs induced C. albicans apoptosis. In conclusion, this proof-of-concept study provides a potential alternative drug-free strategy for killing pathogenic Candida species.