Effects Of Squalene Monooxygenase On Growth And Resistance Of Rhodotorula Mucilaginosa

Background: Rhodotorula mucilaginosa is known as an opportunistic pathogen which caused many diseases especially fungemia and onychomycosis.Naftifine antifungal drug is an inhibitor of squalene monooxygenase,which inhibits the synthesis of pathway,causing accumulation of squalene to cause fungal death.It has been discovered naftifine was able to counterproductively inhibit the pigmentation of R.mucilaginosa.This study was conducted to investigate the effects of naftifine and assess the growth and survival of R.mucilaginosa by macrophages phagocytosis assay and cultivation under different conditions.Objectives: To observe the effect of squalene monoxygenase on growth and survival rate R.mucilaginosa under different conditions.Methods: R.mucilaginosa was identified by using morphological and molecular methods followed by naftifine-reversible effect test.Survival and resistance rate of the R.mucilaginosa were assessed by phagocytosis assay,thermotolerance test,naftifine susceptibility test and cultivation on agar medium supplemented with different types of chemical.Squalene mooxygenase gene(Erg1)was cloned into pPIC9 k vector and expressed in Pichia pastoris system.Results:1.Isolation and identification of R.mucilaginosa,and Naftifine acted as reversible inhibitor on R.mucilaginosa at minimum concentration(0.2mg/mL).2.Naftifine induced depigmentation of R.mucilaginosa and increased susceptibility towards murine macrophage cells and reduce the resistance.3.Depigmented R.mucilaginosa by naftifine reduced the resistance and survival towards 1% SDS,1.5M NaCl and 0.5% congo red.4.The recombinant gene Erg1-pPIC9 K was successfully constructed and cloned into Escherichia coli(JM190)and P.pastoris(GS115)cells.Conclusion: Our result showed inhibition of SQLE affected the survival growth and resistance of R.mucilaginosa on heat,1% SDS,1.5M NaCl and 0.5% congo red.