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

Abstract

The adhesion of Candida albicans to the genital epithelium has not been fully investigated in vivo. The objective of this study was to evaluate the ultrastructural aspects of C. albicans adhesion 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 for in vivo studies. Continuation of this line of research is important for studies of vulvovaginal candidiasis.

Scanning Electron and Confocal Scanning Laser Microscopy Imaging of the Ultrastructure and Viability of Vaginal Candida albicans and Non-Albicans Species Adhered to an Intrauterine Contraceptive Device

“…Metallization in gold was carried out in a Balzers SCD-030. The adhesion of all the yeasts tested on the IUD parts was observed and photographed with the use of a JEOL-JSM 6360 LV scanning electron microscope (JEOL Ltd., Tokyo, Japan) (Chassot et al, 2008; Damke et al, 2010) at the Electron Microscopy Center, Federal University of Paraná.…”

Sterol uptake by the NPC system in eukaryotes: a Saccharomyces cerevisiae perspective

“…The extracellular surface of fungi, bacteria and mammalian cells is covered by a meshwork of various sugars interconnected in many ways to form conjugates called glycans [67][68][69]. Glycans can aggregate with each other (glycopolymers) or bind to lipids (glycolipids) and proteins as elaborate branched structures (glycoproteins) or as unbranched chains of tens of thousands of monosaccharides (proteoglycans).…”

“…In contrast, increased levels of particular glycans and the overall thickness of the glycocalyx promote tumour metastasis and hinder phagocytosis by obstructing receptor-mediated macrophage binding [69,71,74]. The glycocalyx also influences the shape of cells and host-pathogen interactions [67,75].…”

Conformational changes in the Niemann-Pick Type C1 protein NCR1 drive sterol translocation

“…This tunnel is formed at the interface between a middle luminal domain (MLD) and a C-terminal domain (CTD) (Fig. 1B) (Damke et al, 2010; Winkler et al, 2019). Transport refers to the movement of sterols through this tunnel before their release into the luminal leaflet of the membrane (Winkler et al, 2019; Winkler et al, 2022).…”