Study On Detecting Methods And Drug-Resistance Mechanism Of Fluconazole In Canida Albicans

[Objective]:To study on the detecting methods of Candida albicans, and evaluate the feasibility of their application in the clinical laboratory. To investigate the drug-resistance mechanism of Candida albicans to azoles, and provide objective evidences to rational use of antibiotics.[Methods]:We collected 253 of clinical isolates of Candida albicans from outpatients and inpatients of the first affiliate hospital of Anhui medical university, all of the isolates were tested for susceptibility to fluconazole by disk diffusion method proposed by NCCLS (M44-p), microdilution method proposed by NCCLS(M27-A) and broth microdilution method (ATB FUNGUS2 biomeriux france) .mean while we used microdilution method proposed by NCCLS as standard method, and compared the other two methods with coincidence rates, sensitivities and specificities. Then microdilution method and broth microdilution method (ATB FUNGUS2 biomeriux france) were adopted to detect the MIC of all of the Candida albicans, and we analysed the drug-resistance of clinical antibiotics used frequently, such as FLZ, 5-FC, ITR, AMPHO and VRC.[Results]:1,Among 253 clinical isolates of Candida albicans we found 11 drug-resistance Candida albicans by disk diffusion method proposed by NCCLS. the total detection rate was 4.3﹪;and by microdilution method we found 12 drug-resistance candida albicans, the positive rate was 4.7﹪;and by broth microdilution method (ATB FUNGUS2 biomeriux france) we found 16 drug-resistance candida albicans, the total detection rate was 6.3﹪.2,compared with microdilution method proposed by NCCLS, the agreements of the ATB FUNGUS2 was 97.2﹪,the sensitivity was 63.2﹪,and specificity was 98.2﹪.the coincidence rate of disk diffusion method proposed by NCCLS(M44-p) was 95.6﹪, the sensitivity was 66.7﹪,and specificity was 98.6﹪.3,the drug sensitive rate of FLZ,ITR,AMB,5-FC and VRC was 87.8﹪,78.7﹪,98.8﹪,82.2﹪to Candida albicans.4,the situation of drug-resistance to candida albicans was very serious.[conclusions]:1,the fluconazole-resistant candida strains perform significant roles in the deep infection of fungus.2,compared with disk diffusion method proposed by NCCLS, broth microdilution method (ATB FUNGUS2 biomeriux france) has higher accuracy,sensitive and specificity,and can be operated conveniently, and it can report five kind of antifungal drugs, so broth microdilution method (ATB FUNGUS2 biomeriux france) can be applied to detect drug-resistance candida albicans isolates in the clinical laboratories.3,FLZ can be used in treating infections caused by candida albicans frist,and FLZ and 5-FC could be selected unitedly in treating this kind of infections. [Abstract] [Objective]:To study the relation between Fluconazole -resistance mechanism of Candida albicans with mutation in ERG11 gene, and determine the mechanism of drug-resistance to azole in Candida albicans.[Methods]: 253 of clinical isolates of Candida albicans were separated from sputum,blood and urine, all of the isolates were tested for susceptibility to fluconazole by microdilution method proposed by NCCLS(M27-A),and 2 strains of Fluconazole-resistant Candida albicans and 7 strains of Fluconazole-susceptible Candida albicans were used to amplify ERG11 gene by PCR,using Candida albicans genomic DNA extracts as the templates and the DNA sequences of PCR products were analyzed by using BLAST and CLUSTAL softwares.[Results] Among 2 strains of Fluconazole- susceptible Candida albicans we didn′t found out mutation of ERG11 gene, meanwhile we found mutation from 7 Fluconazole-resistant Candida albicans.[conclusions] Drug-resistance mechanism to azole in Candida albicans is correlated with gene mutation of T199I and E165Y in ERG11 gene.