In vitro antifungal activity of silver nanoparticles against resistant Candida species

Introduction and objectives: Candida albicans is a pleomorphic fungus which is a normal commensal in healthy individuals; however, as an opportunistic pathogen, C. albicans is the most common etiological agent of candidiasis, now the fourth most frequent infection in the US hospitals, mostly due to the increasing numbers of susceptible compromised patients that are at risk of this systemic fungal infection. Resistance of pathogenic fungi to conventionally available antifungal agents has been increasing and has become a serious problem. On the other hand, nanoscience has emerged as a powerful tool capable of developing and designing new antifungal drugs. The aim of this study was to test minimum inhibitory concentrations (MICs) of silver nanoparticle on 10 fluconazole and itraconazole resistant C. albicans strains. These strains were isolated from diabetic patients. Material & Methods: The study group consisted of 10 C. albicans resistant strains isolated from oral cavity of adult diabetic patients. These strains were resistant to antifungal agents (5 fluconazole and 5 itraconazole resistant. The standard strain of C. albicans (ATCC 10231) as a control were used in this study. The standard protocol of antifungal susceptibility testing for yeast was performed by the broth micro-dilution method described in the clinical and laboratory standards institute (CLSI) guidelines, documentM27-S3. Results: MICs of standard and resistant strains were different against silver nanoparticle. MIC was reduced by Ag-NPs in 3 and 2 fluconazole resistant strains by 16 and 4-fold, respectively. About 5 itraconazole resistant strains, MIC were reduced in 2 and 3 fluconazole resistant strains by 8 and 4-fold, respectively. Conclusion: The results demonstrated that silver nanoparticle had higher activity than azole agents. Therefore, new antifungals are an unavoidable and critical medical need. Consideration of the possibility of oral Candida infections in diabetic patients is emphasized for improving patient treatment outcomes andreducing healthcare costs.

کلیدواژه ها:

Candida albicans ، Silver nanoparticle ، Antifungal drug resistant strains