ASSESSMENT OF CATALASE AND GLIOTOXIN CYTOTOXICITY IN ASPERGILLUS FLAVUS FUNGAL

Background and Aim:Aspergillus flavus is one of the most common causes of fungal infections in immunocompromised patients due to its pathogenic virulence factors such as catalase and Gliotoxin in this fungus. In this study, the catalase activities and cytotoxic effects of gliotoxin were comparedin environmental and clinical isolates of Aspergillus flavus.Methods:Ten clinical samples of Aspergillus flavus from immunocompromised patients and ten environmental samples were collected and identified by culture and PCR-RFLP, using MwoI restriction enzyme. Catalase were extracted from spores and mycelia phase of cultures and evaluated by Amplex Red catalase assay Kit (A22180).The cytotoxicity of gliotoxin on MRC-5 lung cell lines was evaluated by XTT test.Results:: All the samples were proved as Aspergillus flavus by PCR-RFLP. Mycelia catalase measures in clinical samples were more than the ones found in environmental samples (p> 0.05), but catalase measures from spores in both groups were equal. Mycelia catalase in all 20 species were significantly higher than spore catalase (p<0.05).There was no any significant difference in cytotoxicity of gliotoxinin both sample kinds (p> 0.05).Conclusion:The previous studies don’t enable us to determine the virulence factors of Aspergillus flavus. It has been demonstrated that Mycelial phase had more catalase activity; therefore it is more pathogenic and it can be concluded that Cytotoxicity of gliotoxin on lung cell lines in both clinical and environmental samples was identical.

Keywords:

Aspergillus flavus , catalase , mycelium , spore , PCR-RFLP , gliotoxin , XTT