Anticandidal Efficacy of Green Synthesized Silver Nanoparticles Using Trans-Himalayan Plant Extracts Against Drug Resistant Clinical Isolates of Candida auris

Abstract

Candida auris is the most common, globally detected nosocomial fungal pathogen with multi-drug resistance. The high prevalence of C. auris infections has raised concern about drug resistance and adverse effects, compounded by a lack of effective alternative drugs. Bioengineered nanomaterials play a significant role in combating nosocomial infections. Silver nanoparticles (AgNPs) have emerged as an extensively used nanomaterial due to their prominent antimicrobial properties. One of the most promising approaches is to incorporate herbal extracts that contain a range of phytoconstituents, being used for curing various chronic illnesses. This study aimed to produce eco-friendly, cost-effective green synthesized AgNPs with trans-Himalayan medicinal plant extracts (Trillium govanianum & Bergenia ligulata) and assess their anticandidal and antibiofilm potential. The green-synthesized AgNPs formation and crystalline nature were confirmed by UV–visible spectroscopy, dynamic light scattering and X-ray diffraction analysis. The UV–Vis spectra of the AgNPs revealed bands in the range of 415–430 nm. Phytoconstituents as reducing agents were involved in the stabilization of AgNPs as identified by FTIR spectra. HR-TEM of AgNPs’ displayed a spherical shape with size in the range of 10–100 nm. Results of activity tests performed using various C. auris clinical strains showed half maximum growth inhibition (IC₅₀) at 8.02 µg/mL, which inhibited 65% of biofilm for T. govanianum extract. The free radical scavenging activity evaluated for green synthesized AgNPs using DPPH showed more than 90% antioxidant activity. Green synthesized AgNPs displayed potent growth inhibition (IC₅₀) at 4.01 µg/mL with 87.0% biofilm inhibition. Green synthesized AgNPs coated bandages and catheters inhibited the growth of C. auris. This study concluded that green synthesized AgNPs formulation in conjunction with antifungal agents exhibits potential biomedical application and also could be used as alternative therapeutics.