Inhibition of biofilm- and hyphal- development, two virulent features of Candida albicans by secondary metabolites of an endophytic fungus Alternaria tenuissima having broad spectrum antifungal potential

Publication date: Available online 28 November 2019Source: Microbiological ResearchAuthor(s): Sohini Chatterjee, Ranjan Ghosh, Narayan Chandra MandalAbstractFungal resistance against frequently used antifungal medicines used for invasive candidiasis and other fungal infections is directing scientist for searching and developing novel antifungal drugs. An endophytic fungal strain Alternaria tenuissima OE7 has been isolated from leaves of Ocimum tenuiflorum L. which showed antifungal activity against numbers of human pathogenic fungi including Trichophyton rubrum, Microsporum gypseum, Aspergillus parasiticus, A. flavus, A. fumigates, Candida albicans and C. tropicalis. Thermostable, non-proteinacious antifungal metabolites produced zones of inhibition against all pathogenic fungi tested. The ethyl acetate extract of the cell free supernatant was found inhibitory to the radial growth and conidial germination of T. rubrum and M. gypseum. It also showed cidal mode of action against C. albicans at a concentration of 1.0 mg/ml. Most interestingly, inhibition of biofilm formation and hyphal development of C. albicans were observed upon treatment with EA fraction at comparatively lower concentrations (100- 500 µg/ml). Release of intracellular contents from treated cells of Candida and scanning electron microscopic observation suggested cellular disruptions by antifungal metabolites. Checkerboard study revealed synergy between EA fraction of OE7 (150 µg/ml) and fluconazole (30â...
Source: Microbiological Research - Category: Infectious Diseases Source Type: research