Exploration Of Marine Crustacean Associated Microorganisms For Their Bioactive Potential Against Candida Albicans And Their Virulence Factors

Abstract

Candida albicans, an opportunistic fungal pathogen, is widely found in the oral cavity, urinary and gastrointestinal tract of human. C. albicans establishes infection and shows antimicrobial resistance to conventional antibiotics due to its various capabilities of producing virulence factor. Among them, few include biofilm production, secretion of enzymes involved in virulence, filamentation and phenotypic switching. Biofilm-mediated multidrug resistance has turned into major challenge for the treatment of C. albicans infections. In the present study, a total of 85 actinobacteria were isolated from marine crustaceans, of which 34 isolates were morphologically distinct with Streptomyces as the major genera. The distinct isolates were investigated for their ability to inhibit C. albicans by well diffusion method, where isolate SS5 was selected as potent due to its excellent activity against target pathogen and was identified as Streptomyces diastaticus SS5 by morphological, cultural, biochemical, physiological and molecular characterization. Further, the antifungal crude metabolite was produced by submerged fermentation process. Ethyl acetate bioactive fractions newline(6 and#956;g mLand#8722;1) from SS5 showed potent antibiofilm activity against newline newlineC. albicans. Light microscopic and CLSM analysis further substantiated the antibiofilm activity of the bioactive fraction against C. albicans. Further the antifungal compound was purified from SS5. The compound was characterized using various spectroscopic techniques (FTIR, 1H and newline13C NMR) and named Eicosane. Compound Eicosane showed newline newlinesignificant biofilm inhibitory activity against C. albicans and resulted in severe morphological aberrations in their structure. Moreover, light microscopic and CLSM investigation unveiled the significant reduction newline newline newline newlinein the adhesion and colonization of yeast cells to the matrix on Eicosane treated samples. The results were well corroborated with SEM micrograph in which pellucid gap between the cells were observed and c