Objectives:By assessing and comparing the phenotypic changes on the stepwise acquisition of fluconazole resistant Candida albicans isolates,we could find and describe the relationship between drug resistance and biofi...Objectives:By assessing and comparing the phenotypic changes on the stepwise acquisition of fluconazole resistant Candida albicans isolates,we could find and describe the relationship between drug resistance and biofilm formation ability in a series of clonal strains.Methods:We performed antifungal susceptibility of five drugs(fluconazole,itraconazole,voriconazole,caspofungin and amphotericin B)to further verify the antifungal activity of the six isolates in vitro.Then we combined hyphal formation assay,cell surface hydrophobicity test positively related to adherence ability,and biofilm assays in vitro to observe and compare the phenotypic characteristics of our six clonal strains.Results:Biofilm capability is enhanced for four drug-intermediate strains,whereas the initial susceptible strain and the final resistant strain are both poor in adherence,hyphal growth and biofilm formation.Conclusions:It was suggested that the biofilm formation ability were not absolutely related to the degree of fluconazole resistance.展开更多
Multi-drug resistance of pathogenic microorganisms is becoming a serious threat,particularly to immunocompromised populations.The high mortality of systematic fungal infections necessitates novel antifungal drugs and ...Multi-drug resistance of pathogenic microorganisms is becoming a serious threat,particularly to immunocompromised populations.The high mortality of systematic fungal infections necessitates novel antifungal drugs and therapies.Unfortunately,with traditional drug discovery approaches,only echinocandins was approved by FDA as a new class of antifungals in the past two decades.Drug efflux is one of the major contributors to multi-drug resistance,the modulator of drug efflux pumps is considered as one of the keys to conquer multi-drug resistance.In this study,we combined structure-based virtual screening and whole-cell based mechanism study,identified a natural product,beauvericin(BEA)as a drug efflux pump modulator,which can reverse the multi-drug resistant phenotype of Candida albicans by specifically blocking the ATP-binding cassette(ABC)transporters;meantime,BEA alone has fungicidal activity in vitro by elevating intracellular calcium and reactive oxygen species(ROS).It was further demonstrated by histopathological study that BEA synergizes with a sub-therapeutic dose of ketoconazole(KTC)and could cure the murine model of disseminated candidiasis.Toxicity evaluation of BEA,including acute toxicity test,Ames test,and hERG(human ether-a-go-go-related gene)test promised that BEA can be harnessed for treatment of candidiasis,especially the candidiasis caused by ABC overexpressed multi-drug resistant C.albicans.展开更多
基金National Science and Technology Major Project(No.2018ZX10734404-007 to Liu WD)the CAMS Initiative for Innovative Medicine[Grant No.2016-I2M-3-021 to(Liu WD&Li XF)]+2 种基金National Natural Science Foundation of China(No.81573059 to Li XF,No.81903229 to Zhou XW)the PUMC Youth Fund&Fundamental Research Funds for the Central Universities(Grant No.2017310033 to Zhou XW)the Basical Scientific Research Fund Projects of Chinese Academy of Medical Sciences(No.2018PT31013 to Liu WD).
文摘Objectives:By assessing and comparing the phenotypic changes on the stepwise acquisition of fluconazole resistant Candida albicans isolates,we could find and describe the relationship between drug resistance and biofilm formation ability in a series of clonal strains.Methods:We performed antifungal susceptibility of five drugs(fluconazole,itraconazole,voriconazole,caspofungin and amphotericin B)to further verify the antifungal activity of the six isolates in vitro.Then we combined hyphal formation assay,cell surface hydrophobicity test positively related to adherence ability,and biofilm assays in vitro to observe and compare the phenotypic characteristics of our six clonal strains.Results:Biofilm capability is enhanced for four drug-intermediate strains,whereas the initial susceptible strain and the final resistant strain are both poor in adherence,hyphal growth and biofilm formation.Conclusions:It was suggested that the biofilm formation ability were not absolutely related to the degree of fluconazole resistance.
基金the National Program on Key Basic Research Project(973program,2013CB734000)in part by grants from the National Natural Science Foundation of China[31670052,31430002,31320103911,31400090,81302678 and 31125002]+2 种基金the Ministry of Science and Tech-nology of the People’s Republic of China[2011ZX09102-011-11,2013ZX10005004-005]China Ocean Mineral Resources R&D Association(Grant No.DY125-15-T-07)the European Union’s Seventh Framework Programme(FP7/2007-2013)under grant agreement no.312184.
文摘Multi-drug resistance of pathogenic microorganisms is becoming a serious threat,particularly to immunocompromised populations.The high mortality of systematic fungal infections necessitates novel antifungal drugs and therapies.Unfortunately,with traditional drug discovery approaches,only echinocandins was approved by FDA as a new class of antifungals in the past two decades.Drug efflux is one of the major contributors to multi-drug resistance,the modulator of drug efflux pumps is considered as one of the keys to conquer multi-drug resistance.In this study,we combined structure-based virtual screening and whole-cell based mechanism study,identified a natural product,beauvericin(BEA)as a drug efflux pump modulator,which can reverse the multi-drug resistant phenotype of Candida albicans by specifically blocking the ATP-binding cassette(ABC)transporters;meantime,BEA alone has fungicidal activity in vitro by elevating intracellular calcium and reactive oxygen species(ROS).It was further demonstrated by histopathological study that BEA synergizes with a sub-therapeutic dose of ketoconazole(KTC)and could cure the murine model of disseminated candidiasis.Toxicity evaluation of BEA,including acute toxicity test,Ames test,and hERG(human ether-a-go-go-related gene)test promised that BEA can be harnessed for treatment of candidiasis,especially the candidiasis caused by ABC overexpressed multi-drug resistant C.albicans.
