不同序列型禽白念珠菌体外药物敏感性与生物被膜试验

Drug Susceptibility and Biofilm of Different Sequence Types of Avian Candida albicans

对不同序列型(STs)禽白念珠菌进行体外常规抗真菌药物的敏感性和生物被膜形成检测,以便了解其耐药性、生物膜形成的差异和相关性,为临床抗白念珠菌药物的选择提供参考。采用纸片扩散法和最小抑菌浓度法进行药物敏感性试验;用96孔板结晶紫法进行生物被膜形成试验。结果显示:菌株YAN对供试药物卡泊芬净、伏立康唑、氟康唑、伊曲康唑、酮康唑和两性霉素B均表现敏感;菌株BDK8、BYCSF和ZU1-2对4种唑类药物耐药;BDK8对卡泊芬净和和两性霉素B敏感;BYCSF和ZU1-2对卡泊芬净中度敏感,对两性霉素B敏感。氟康唑对试验菌株BDK8、ZU1-2、BYCSF和YAN的MIC分别为>64μg/mL、64μg/mL、64μg/mL和8μg/mL;两性霉素B对上述菌株的MIC依次为0.25μg/mL、0.50μg/mL、0.125μg/mL和0.25μg/mL。试验菌株的生物被膜形成能力为YAN(2.19)>BYCSF(1.78)>ZU1-2(1.73)>BDK8(0.92)。研究表明,代表本地区主要克隆群的禽源白念珠菌不同STs菌株对常用抗真菌药物的药敏谱和耐药强度差异显著,说明禽源白念珠菌种群具有耐药表型和遗传的多样性;白念珠菌生物被膜形成能力与其它耐药表型并没有必然联系。

To detect the susceptibility of conventional antifungal agents and biofilm formation in vitro for different sequence types(STs)of Candida albicans,and to understand the difference and correlation between drug resistance and biofilm formation,so as to provide basis for the selection of clinical antifungal agents and the development of new drugs.Drug susceptibility test was carried out by disc diffusion method and minimum inhibitory concentration method,and biofilm formation was carried out by 96-well plate crystal violet method.Strain YAN was sensitive to all tested drugs(caspofungin,voriconazole,fluconazole,itraconazole,ketoconazole and amphotericin B);strain BDK8,BYCSF and ZU1-2 were resistant to the four azole drugs;BDK8 was sensitive to caspofungin and amphotericin B;and BYCSF and ZU1-2 were moderately sensitive to caspofungin and sensitive to amphotericin B.The MICs of fluconazole against the tester strains were BDK8(>64μg/mL),ZU1-2(64μg/mL),BYCSF(64μg/mL)and YAN(<8μg/mL)in descending order;The MICs of amphotericin B against the above strains were 0.25μg/mL,0.50μg/mL,0.125μg/mL and 0.25μg/mL,respectively.The biofilm forming ability of the tester strains was YAN(2.19)>BYCSF(1.78)>ZU1-2(1.73)>BDK8(0.92),which was negatively related to the drug sensitivity.In conclusion,the drug sensitivity of different STs strains of avian Candida albicans,representing the main clonal complexes in this region,differ significantly,indicating that the population of avian Candida albicans has a diversity of drug resistance phenotypes and heredity,and the activity of biofilm formation of Candida albicans is not necessarily related to other drug resistance phenotypes.