Ultrastructural Imaging ofCandida albicansAdhesion to Rat Genital Epithelium through Scanning and Transmission Electron Microscopy

Abstract The adhesion ofCandida albicansto the genital epithelium has not been fully investigatedin vivo. The objective of this study was to evaluate the ultrastructural aspects ofC. albicansadhesion in the lower genital system of female Wistar rats through scanning and transmission electron microscopy. The genital infection persisted until the end of the experiment, and all rats showed the same adhesion aspects. Various associated yeast/hyphae were observed in the lumen and adhered both at the vaginal and endocervical levels where the fungal filamentation process occurred. In the vaginal epithelium, closely adhered yeasts were observed as stretched strands bridging between yeasts and the epithelium surface. Different stages of the adhesion, where yeasts internalized into the epithelial cell inside a cytoplasmic vacuole, resembling endocytosis, and a wide fibrillar-floccular, glycocalyx-like layer on the yeasts were observed. On the endocervix, the adhesion occurred between the cilia. In the uterine body, only a yeast-like form was observed with superficial contact. This study reached the initial goal of demonstrating an experimental model forin vivostudies. Continuation of this line of research is important for studies of vulvovaginal candidiasis.