Sun Jing, Li Zhigang, Chu Haoyue, Guo Jing, Jiang Guangshui, Qi Qingguo
Shandong Provincial Hospital Affiliated to Shandong University, 324 Jingwu Road, Jinan, Shandong, China.
Shandong Provincial Key Laboratory of Oral Biomedicine, 44-1 Wenhuaxi Road, Jinan, Shandong, China.
Mycopathologia. 2016 Feb;181(1-2):41-9. doi: 10.1007/s11046-015-9894-1. Epub 2015 Sep 18.
Candida albicans persisters have so far been observed only in biofilm environment; the biofilm element(s) that trigger(s) persister formation are still unknown. In this study, we tried to further elucidate the possible relationship between C. albicans persisters and the early phases of biofilm formation, especially the surface adhesion phase. Three C. albicans strains were surveyed for the formation of persisters. We tested C. albicans persister formation dynamically at different time points during the process of adhesion and biofilm formation. The number of persister cells was determined based on an assessment of cell viability after amphotericin B treatment and colony-forming unit assay. None of the planktonic cultures contained persisters. Immediately following adhesion of C. albicans cells to the surface, persister cells emerged and the proportion of persisters reached a peak of 0.2-0.69 % in approximately 2-h biofilm. As the biofilm matured, the proportion of persisters decreased and was only 0.01-0.02 % by 24 h, while the number of persisters remained stable with no significant change. Persisters were not detected in the absence of an attachment surface which was pre-coated. Persisters were also absent in biofilms that were scraped to disrupt surface adhesion prior to amphotericin B treatment. These results indicate that C. albicans antifungal-tolerant persisters are produced mainly in surface adhesion phase and surface adhesion is required for the emergence and maintenance of C. albicans persisters.
到目前为止,仅在生物膜环境中观察到白色念珠菌持留菌;触发持留菌形成的生物膜成分仍然未知。在本研究中,我们试图进一步阐明白色念珠菌持留菌与生物膜形成早期阶段,尤其是表面黏附阶段之间的可能关系。对三株白色念珠菌菌株进行了持留菌形成情况的调查。我们在黏附及生物膜形成过程中的不同时间点动态测试了白色念珠菌持留菌的形成情况。基于两性霉素B处理后的细胞活力评估和菌落形成单位测定来确定持留菌细胞的数量。所有浮游培养物中均未含有持留菌。白色念珠菌细胞黏附到表面后,立即出现持留菌细胞,在约2小时的生物膜中持留菌比例达到0.2 - 0.69%的峰值。随着生物膜成熟,持留菌比例下降,到24小时时仅为0.01 - 0.02%,而持留菌数量保持稳定,无显著变化。在没有预先包被的附着表面时未检测到持留菌。在两性霉素B处理前刮擦以破坏表面黏附的生物膜中也不存在持留菌。这些结果表明,白色念珠菌抗真菌耐受持留菌主要在表面黏附阶段产生,表面黏附是白色念珠菌持留菌出现和维持所必需的。