标题：Inhibition of Nucleic Acid Biosynthesis Makes Little Difference to Formation of Amphotericin B-Tolerant Persisters in Candida albicans Biofilm
作者：Sun, Jing;Liu, Xiaohua;Jiang, Guangshui;Qi, Qingguo
作者机构：Shandong Univ, Shandong Prov Key Lab Oral Biomed, Jinan 250100, Shandong, Peoples R China;Jinan Stomatol Hosp, Jinan, Shandong
来源：Antimicrobial agents and chemotherapy.
摘要：Candida albicans persisters constitute a small subpopulation of biofilm cells and play a major role in recalcitrant chronic candidiasis; however, the mechanism underlying persister formation remains unclear. Persisters are often described as dormant, multidrug-tolerant, nongrowing cells. Persister cells are difficult to isolate and study not only due to their low levels in C. albicans biofilms but also due to their transient, reversible phenotype. In this study, we tried to induce persister formation by inducing C. albicans cells into a dormant state. C. albicans cells were pretreated with 5-fluorocytosine (planktonic cells, 0.8 mu g ml(-1); biofilm cells, 1 mu g ml(-1)) for 6 h at 37 degrees C, which inhibits nucleic acid and protein synthesis. Biofilms and planktonic cultures of eight C. albicans strains were surveyed for persisters after amphotericin B treatment (100 mu gml(-1) for 24 h) and CFU assay. None of the planktonic cultures, with or without 5-fluorocytosine pretreatment, contained persisters. Persister cells were found in biofilms of all tested C. albicans strains, representing approximately 0.01 to 1.93% of the total population. However, the persister levels were not significantly increased in C. albicans biofilms pretreated with 5-fluorocytosine. These results suggest that inhibition of nucleic acid synthesis did not seem to increase the formation of amphotericin B-tolerant persisters in C. albicans biofilms.