The role of cell density in the morphology of the Candida albicans bioflims development and the tyrosol production / 中华微生物学和免疫学杂志

ABSTRACT

Objective To study the role of cell density in the tyrosol production and morphology for Candida albicans biofilms. Methods C. albicans SC5314 and clinical isolates were propagated in yeast peptone dextrose (YPD) medium. Cells were collected by centrifugation and washed twice in sterile phosphate-buffered saline (PBS) before this study, then resuspended in RPMI 1640 supplemented with L-glutamine and adjusted to a desired concentration of 5 × 10~6 cells/ml, 5×10~5 cells/ml, 5 × 10~4 cells/ml, 5 × 10~3 cells/ml after counting with a hematocytometer. Standardized C. albicans cells were prepared as above description and 2000 μl of this standardized cell suspension was dispensed into the wells, then C. albicans biofilms were formed on the bottom of the polystyrene wells. In this study, tyrosol synthesized by SC5314 and clinical isolates of C. albicans biofilm was quantified by high performance liquid chromatography (HPLC). The effects of tyrosol on morphology of C. albicans biofilms were investigated by scanning electron microscopy (SEM). Results Tyrosol production of C. albicans biofilms was affected by cell densities. At lower inoculation size(5 μ 10~3 cells/ml), there was too less tyrosol production to be detected at the early stage of the biofilms formation. At higher inoculation size (5 μ10~6 cells/ml), tyrosol can be detectable at the early stage or at the mature stage of biofilms formation. There was a sharp increase in tyrosol concentration at 24 h, while there was a decrease in tyrosol concentration after that time from the strains when the strains were at an inoculation size of 5 × 10~6 cells/ml and 5 × 10~5 cells/ml. Cell densities affected the morphology formation of the C. albicans biofilms. At the early stage of the biofilms formation, C. albicans grew less germ tube at lower cell densities than that at the higher cell densities. With the mature of the biofilms, C. albicarts grew more hyphae at higher cell densities than that at the lower cell densities. All these above showed that cell densities played an important role in the propagation for the C. albi-cans in the biofilm formation. Conclusion Cell density play an important role in the formation of the C. albi-cans biofilms and the production of the tyrosol.