Mutation of P927S in PRD1 gene mediates azole resistance in Candida glabrata / 中华传染病杂志

ABSTRACT

Objective To investigate the role of PDR1 gene in azole-resistant Candida glabrata (C.glabrata).Methods Thirty-eight clinical isolates of C.glabrata were collected from five different hospitals.The minimal inhibitory concentrations (MIC) of azole antifungals including fluconazole,itraconazole and voriconazole against C.glabrata were determined by broth microdilution.Sequencing and amplification of PDR1 gene was achieved by real-time quantitative polymerase chain reaction (PCR).The mutation was cloned into an expression plasmid and then transferred into C.glabrata.The efflux of rhodamine 6G and drug sensitivity test were performed,and expressions of CDR1 and CDR2 were examined to verify function of mutation.Results Among these 38 isolates of C.glabrata,17 were resistant to at least one of azole antifungals.Moreover,mutations of PDR1 gene existed in every resistant isolates.Results of phenotyping test showed that in the isolate that expressed PDR1P927S,the expression of CDR1 and CDR2 were increased by 20.53 and 4.03 fold,respectively.And the fluorescence intensity of rhodamine 6G was decreased to 0.62 in efflux experiment.Conclusion P927S mutation of PDR1 gene could induce azole resistance of C.glabrata by increasing the expressions of CDR1 and CDR2,which results in drug resistance due to enhanced effect of efflux pump.