Investigation of cgrA and cyp۵۱A gene alternations in Aspergillus fumigatus strains exposed to kombucha fermented tea

Background and Purpose: Aspergillus fumigatus is one of the most common opportunistic fungus, which causes infection in immunocompromised and neutropenic patients. The current guidelines recommend voriconazole as the initial therapeutic and prophylactic agent for almost all cases, especially in patients with organ transplants, which leads to increased medication resistance in A. fumigatus. The aim of the present study was to evaluate the antifungal activity and effect of kombucha as a natural compound on A. fumigatus growth, as well as on the expression of cgrA and cyp۵۱A genes. Materials and Methods: A panel of ۱۵ A. fumigatus strains with two quality controls of CM۲۳۷ and CM۲۶۲۷ as susceptible and resistant strains were obtained from Tehran Medical Mycology Laboratory, Tehran,Iran(TMML).Antifungal susceptibility testing assay was performed according to the Clinical and Laboratory Standards Institute (CLSI) M۳۸-A۲ document. Moreover, the mycelial dry weight of the fungus was calculated before and after being treated with kombucha. In addition, the quantitative changes in the expression of cgrA and cyp۵۱A genes were analyzed by real-time polymerase chain reaction (real-time PCR) technique. Results: In the present study, the minimum inhibitory concentration ranges of kombucha were measured at ۶,۱۷۰ and ۱۲,۳۰۰ μg/mL for ten A. fumigatus azole-susceptible strains and ۲۴,۷۰۰ μg/mL for five A. fumigatus resistant strains. Moreover, changes in mycelial dry weight under kombucha treatment conditions underwent a significant reduction (P≤۰.۰۵). A coordinate down-regulation of expression in cgrA and cyp۵۱A genes was observed in all azole-susceptible and -resistant A. fumigatus strains, after treating the fungus with different concentrations of kombucha (P≤۰.۰۵). Conclusion: According to the obtained results, kombucha as a natural antioxidant , can exert inhibitory effects against the growth and expression of some genes in A. fumigatusstrains.

Keywords:

Aspergillus fumigatus , CgrA gene , Cyp۵۱A gene , Kombucha