FIRST REPORT OF DIMORPHISM IN ASPERGILLUS VERSICOLOR ISOLATED FROM FRESH WATER FISH HETEROPNEUSTES FOSSILIS
Karuna Singh, Jyoti Rani and Neelabh
Abstract
The morphologic conversion of the dimorphic fungi from mold to yeast is required for virulence. Conversion from mold to yeast form may offer protection against killing by neutrophils, monocytes and macrophages. Aspergillus versicolor is a cosmopolitan fungus which rarely causes deep infections in humans. It is an occasional agent of onychomycosis. Here we report the dimorphism in Aspergillus versicolor isolated from skin of Heteropneustes fossilis. Cultures of A. versicolor were grown on SDA (Sabouraud Dextrose Agar) at 250 and 370 for 15 days. The pathogen grew well at both the temperatures. Micro morphology at 250 C exhibited normal branching of the hyphae along with formation of conidiophores and conidia. But after 10 days at 370C, hyphae began to convert into chains of conidia and up to 15th day well defined yeast like capsules were found. Yeast like budding was also seen. This study suggests that Aspergillus versicolor itself could be a potential pathogen of warm blooded animals because it possesses dimorphism and has the ability to grow well at 37oC.