Division of Microbiology, Department of Oral Medicine and Periodontology, Faculty of Dental Sciences, University of Peradeniya, Peradeniya, Sri Lanka.
Mycopathologia. 2011 Apr;171(4):235-50. doi: 10.1007/s11046-010-9373-7. Epub 2010 Oct 22.
Commensal yeast Candida causes opportunistic infections ranging from superficial lesions to disseminated mycoses in compromised patients. Superficial candidiasis, the commonest form of candidal infections, primarily affects the mucosa and the skin where Candida lives as a commensal. Conversion of candidal commensalism into opportunism at the fungal-epithelial interface is still ill-defined. Nevertheless, fungal virulence mechanisms such as adhesion to epithelia, morphogenesis, production of secretory hydrolytic enzymes, and phenotypic switching are thought to contribute in the process of pathogenesis. On the other hand, host responses in terms of immunity and local epithelial responses are actively involved in resisting the fungal challenge at the advancing front of the infection. Ultrastructural investigations using electron microscopy along with immunohistochemistry, cytochemistry, etc. have helped better viewing of Candida-host interactions. Thus, studies on the ultrastructure of superficial candidiasis have revealed a number of fungal behaviors and associated host responses such as adhesion, morphogenesis (hyphae and appresoria formation), thigmotropism, production and distribution of extracellular enzymes, phagocytosis, and epithelial changes. The purpose of this review is to sum up most of the ultrastructural findings of Candida-host interactions and to delineate the important pathological processes underlying superficial candidiasis.
共生酵母念珠菌可引起机会性感染，从浅表损伤到播散性真菌感染，使机体处于易感染状态。最常见的念珠菌感染形式——浅表性念珠菌病主要影响黏膜和皮肤，而念珠菌就在这些部位作为共生菌生存。真菌-上皮界面上从共生到机会性的转变仍然难以定义。然而，真菌的毒力机制，如黏附在上皮细胞、形态发生、分泌水解酶的产生以及表型转换，被认为是发病机制中的重要因素。另一方面，宿主的免疫和局部上皮反应在感染进展前沿抵抗真菌侵袭的过程中也积极参与。电子显微镜结合免疫组织化学、细胞化学等超微结构研究有助于更好地观察念珠菌-宿主的相互作用。因此，对浅表性念珠菌病的超微结构研究揭示了许多真菌的行为及其相关的宿主反应，如黏附、形态发生（菌丝和附着胞的形成）、向触性、细胞外酶的产生和分布、吞噬作用和上皮变化。本文综述的目的是总结念珠菌-宿主相互作用的大部分超微结构发现，并阐明浅表性念珠菌病的重要病理过程。
