白假丝酵母菌生物膜中滞留菌形成的动态监测及分析

Dynamic monitoring and analysis of the persisters emerging in Candida albicans biofilm

目的:研究白假丝酵母菌生物膜产生滞留菌的动态特点,为揭示其产生机制及相关途径奠定基础。方法:分别以两相型白假丝酵母菌标准菌液构建体外生物膜模型,CFU计数法统计不同时间段生物膜加药前真菌细胞繁殖数目及加药后滞留菌产生数目,采用SPSS11.5软件包对数据进行统计学分析;结合激光共聚焦显微镜(CLSM),观察生物膜的形态变化。结果:两相型菌液形成的不同时间段生物膜,真菌细胞繁殖数目及滞留菌数目均无显著差异。其中,真菌细胞繁殖数目呈"S"形生长,12 h后渐稳定;滞留菌0.5 h即大量产生,2 h后数目基本稳定,此时镜下生物膜处于微菌落始形成期。结论:白假丝酵母菌滞留菌的形成与其生物膜形成初期(2 h内)附着表面的诱导密切相关,而与生物膜成熟程度及两相型状态无显著关联。

PURPOSE： To investigate the mechanism and approach related to persisters emerging in Candida albicans biofilm by studying its dynamic characteristics. METHODS： The Candida albicans biofilms model in vitro were formed by individual yeast cells and hyphal compartments respectively. The numbers of progenitive fungal cells and persisters at different stages were counted and analyzed with SPSSll.5 software package. The biofilm morphological changes were observed under confocal scanning laser microscopy. RESULTS： Different stages of biofilms which were formed by individual yeast cells and hyphal compartments had no significant difference both on the number of progenitive fungal cells and persisters. The number of progenitive fungal cells showed S-shaped growth curve until 12 hours. The persisters emerged within 0.5 hour and its number reached a steady state after 2 hours while the biofilm was in the period of microcolony formation under microscopy. CONCLUSIONS： The persisters emerging in Candida albicans biofilm are closely connected with the attachment to a surface （within 2 hours of the biofilm formation） and have little association with the maturity of the biofilm and its dimorphism. Supported by National Natural Science Foundation of China（30973310） and Independent Innovation Foundation of Shandong University（2010JQ008）.