Biosynthesis, Characterization, and Antifungal Activity of the Silver Nanoparticles Against Pathogenic Candida species

Due to their high content of biomolecules, combined with silver’s well known antimicrobial potential, silver nanoparticles biosynthesized using spruce bark (AgNP SBEs) demonstrate antibacterial and antioxidant activity, making them a versatile option for developing new antimicrobial agents that might be used for medical treatment or as adjuvants for the classical agents. This study aims to analyze if silver nanoparticles (AgNPs) mediated by spruce bark extract (SBE) and silver salts (AgNP SBE Acetate, AgNP SBE Nitrate) presents antifungal activity against five different Candida spp., synergistic activity with fluconazole, and if they interact with some virulence factors of C. albicans. AgNP SBEs presented MICs (minimum inhibitory concentrations) for all the five tested Candida spp. AgNP SBEs inhibited the growth of C. parapsilosis, C. krusei, and C. guilliermondii, exerted synergistic activity with fluconazole for C. parapsilosis and C. guilliermondii, and inhibited biofilm production for C. albicans, C. auris, and C. guilliermondii. MICs of AgNP SBE Acetate significantly inhibited the production of germ tubes of C. albicans. The expression of C. albicans SAP2 gene was down-regulated by the short-time treatment with MICs of AgNP SBE Acetate, while ALS3 and HSP70 genes were up-regulated by the AgNPs MICs. These results emphasize the potential of using the AgNP SBEs as treatments/adjuvants options, not only against the redundant C. albicans but also for the non-albicans Candida species (which are not as frequently involved in human pathologies, but, sometimes, can be more aggressive).

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Antifungal activity of curcumin-silver nanoparticles against fluconazole-resistant clinical isolates of Candida species

AYU (An International Quarterly Journal of Research in Ayurveda) ◽

10.4103/ayu.ayu_24_18 ◽

2018 ◽

Vol 39 (3) ◽

pp. 182 ◽

Cited By ~ 8

Author(s):

Sony Paul ◽

Kalyani Mohanram ◽

Iyanar Kannan

Keyword(s):

Silver Nanoparticles ◽

Antifungal Activity ◽

Candida Species ◽

Clinical Isolates ◽

Fluconazole Resistant

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Biodirected Synthesis of Silver Nanoparticles Using Aqueous Honey Solutions and Evaluation of Their Antifungal Activity against Pathogenic Candida Spp.

International Journal of Molecular Sciences ◽

10.3390/ijms22147715 ◽

2021 ◽

Vol 22 (14) ◽

pp. 7715

Author(s):

Grzegorz Czernel ◽

Dominika Bloch ◽

Arkadiusz Matwijczuk ◽

Jolanta Cieśla ◽

Monika Kędzierska-Matysek ◽

...

Keyword(s):

Silver Nanoparticles ◽

Antifungal Activity ◽

Fungal Pathogens ◽

Fungal Growth ◽

Disc Diffusion ◽

Candida Spp ◽

Antifungal Effect ◽

Synthesis Of Nanoparticles ◽

Honey Solution ◽

Diffusion Assay

Silver nanoparticles (AgNPs) were synthesized using aqueous honey solutions with a concentration of 2%, 10%, and 20%—AgNPs-H2, AgNPs-H10, and AgNPs-H20. The reaction was conducted at 35 °C and 70 °C. Additionally, nanoparticles obtained with the citrate method (AgNPs-C), while amphotericin B (AmB) and fluconazole were used as controls. The presence and physicochemical properties of AgNPs was affirmed by analyzing the sample with ultraviolet–visible (UV–Vis) and fluorescence spectroscopy, scanning electron microscopy (SEM), and dynamic light scattering (DLS). The 20% honey solution caused an inhibition of the synthesis of nanoparticles at 35 °C. The antifungal activity of the AgNPs was evaluated using opportunistic human fungal pathogens Candida albicans and Candida parapsilosis. The antifungal effect was determined by the minimum inhibitory concentration (MIC) and disc diffusion assay. The highest activity in the MIC tests was observed in the AgNPs-H2 variant. AgNPs-H10 and AgNPs-H20 showed no activity or even stimulated fungal growth. The results of the Kirby–Bauer disc diffusion susceptibility test for C. parapsilosis strains indicated stronger antifungal activity of AgNPs-H than fluconazole. The study demonstrated that the antifungal activity of AgNPs is closely related to the concentration of honey used for the synthesis thereof.

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