Qom University of Medical Sciences Journal

Background and Objectives: In humans, during the recent years, several factors have increased the risk of fungal infections, like broad spectrum antibiotics, immune compromised patients, cytotoxic chemotherapy and transplantations. Among all fungal pathogens Candida species remain the most common cause of invasive fungal infections. The aim of the current study is extraction of lipopeptides from Bacillus atrophaeus HNSQJYH170 isolated from Isfahan, and the study of its antifungal effects against Candida species.

Methods: After 72 h of incubation, a cell-free supernatant of Bacillus atrophaeus was collected by centrifugation and acidified by adding HCl. The precipitate obtained was collected by centrifugation and dissolved in the methanol solution (50 ). Then antifungal activity of lipopeptides was evaluated by well diffusion method against Candida species. Also inhibition effect of lipopeptide on germ tube production for Candida albicans was studied.

Results: There was no Inhibition zone for Candida species by cyclic lipopeptides. Inhibition of germtube production in %95 of C.albicans cells was showed by Bacillus atrophaeus lipopeptides.

Conclusion: The results of this study showed that, although lipopeptides extracted from Bacillus atrophaeus were not able to inhibit Candida spp but inhibition of germtube production in %95 of C.albicans cells was showed. The ability of lipopeptides in inhibition of germtube production in C.albicans was showed, that these compounds can prevent biofilm formation on catheters and other substrate. Therefore, these compounds are important in preventing the invasion C.albicans of mucosal.