The effect of sub minimum inhibitory concentration fluconazole on Sap and biofilm formation of Candida glabrata
Objective To investigate the effects of sub minimum inhibitory concentration(sub-MIC)of fluconazole on the secreted aspartyl protease(Sap)and biofilm formation of Candida glabrata.Methods Clinical isolates of C.glabrata were collected from the Qinghai Provincial People's Hospital from April 2021 to October 2022;the minimum inhibitory concentration(MIC)of fluconazole against C.glabrata was determined by automatic testing bacteriology method.The effect of sub-MIC fluconazole on Sap activity of C.glabrata was detected by bovine serum protein agar medium.The effect of sub-MIC fluconazole on the biofilm formation of C.glabrata was detected by crystal violet method.Reverse transcription-quantitative polymerase chain reaction(RT-qPCR)was used to detect the transcription levels of Sap and biofilm formation related genes in C.glabrata treated with different sub-MIC of fluconazole.It was divided into control group(without fluconazole),1/2MIC fluconazole group,1/4MIC fluconazole group,1/8MIC fluconazole group and 1/16MIC fluconazole group.Results The MIC of fluconazole against 9 clinical isolates of C.glabrata was 8-32 mg/L.Compared with the control group,the Sap activity of C.glabrata was significantly increased in the 1/2MIC fluconazole group(F=5.917,P＜0.05),while there was no significant difference in the 1/4MIC,1/8MIC and 1/16MIC fluconazole groups(all P＞0.05).Fluconazole at 1/2MIC and 1/4MIC significantly stimulated the transcription of YPS3,YPS5 and YPS8 genes(F=4.271,7.551,2.945;all P＜0.05),while fluconazole at 1/8MIC and 1/16MIC had no significant effect on the transcription of YPS3,YPS5 and YPS8 genes(P＞0.05).Compared with the control group,different sub-MICs of fluconazole had no significant effect on the biofilm formation of C.glabrata(P＞0.05),and there were no significant differences in the transcription levels of SNF2,SNF6,EFG1,TEC1 and YAK1 genes among the groups(all P＞0.05).The CST6 gene expression was down-regulated by 1/2MIC fluconazole,compared with the control group,the difference was statistically significant(F=4.002,P＜0.05).There were no significant differences in the expression of CST6 gene among fluconazole at 1/4MIC,1/8MIC and 1/16MIC(all P＞0.05).Conclusions 1/2MIC fluconazole might increase the transcription level of YPS3,YPS5 and YPS8 genes,thereby promoting Sap secretion of C.glabrata.Sub-MIC fluconazole had no significant effect on biofilm formation of C.glabrata.
万方数据
维普
