Investigation of antifungal and antibiofilm activities of green synthesized silver nanoparticles against Candida glabrata.

Abstract

Candida glabrata is an important human fungal pathogen known to cause life-threatening infections in people with impaired immune systems. In the mouth cavities, trachea, and catheters, Candida glabrata biofilm grows unhindered and is the primary etiological factor in the pathophysiology of candidiasis, in the worst cases, this leads to systemic infections. Therefore, developing novel biofilm preventative and therapeutic agents is urgently required. Here, in the present study, an effort was made to monitor the function of silver nanoparticles (AgNPs) generated from a cyanobacterium (Anabaena variabilis) as a novel antibiofilm agent focusing on candidiasis. Anabaena variabilis cell extract was used to synthesize AgNPs, characterized by UV-visible spectroscopy. The minimum inhibitory concentration (MIC) of AgNPs was observed at 25 µg/mL in Candida glabrata. At the concentration of 2MIC of AgNPs (50 µg/mL), 67 ± 0.84% membrane permeability was noticed at the same concentration the viable cells were found at only 2.8 ± 2.0%; while in the early phase of apoptosis, were found at 15.5 ± 1.5%; and in the late phase of apoptosis, were found at 81.8 ± 4.2%, thus confirming the cell's death. Additionally, a cell-cycle study also declared the halted cycle in the S phase by increasing the number of cells. The growth inhibition assay shows that the test organism's growth steadily decreased in comparison to the control with increasing AgNPs concentrations. Additionally, in the scanning electron microscopic pictures of Candida glabrata treated with AgNPs, which exhibited deep wrinkles and deformity, confirming the cells death. At the concentrations of 2MIC of AgNPs (50 µg/mL) showed 72 ± 0.86% of biofilm inhibition and 80 ± 1.3% degradation during the biofilm study. In conclusion, all results demonstrate that AgNPs have great antifungal potential; therefore, AgNPs could be used to control biofilm produced by emerging multidrug-resistant Candida glabrata.