Department of Medical Mycology, Pasteur Institute of Iran, Tehran 1316943551, Iran.
Department of Microbiology, Pasteur Institute of Iran, Tehran 1316943551, Iran.
Iran Biomed J. 2020 Sep;24(5):324-32. doi: 10.29252/ibj.24.5.319. Epub 2020 Feb 19.
The Candida albicans is one of the most important global opportunistic pathogens, and the incidence of candidiasis has increased over the past few decades. Despite the established role of skin in defense against fungal invasion, little has been documented about the pathogenesis of Candida species when changing from normal flora to pathogens of vaginal and gastrointestinal epithelia. This study was carried out to determine the in vivo and in vitro pathogenesis of clinical C. albicans strains isolated from skin lesions.
In this study, association of in vivo and in vitro pathogenesis of C. albicans isolates with different evolutionary origins was investigated. Oral and systemic experimental candidiasis was established in BALB/C mice. The expression levels of secreted aspartyl proteinases (SAP1-3 genes), morphological transformation, and biofilm-forming ability of C. albicans were evaluated.
All the strains showed in vitro and in vivo pathogenicity by various extents. The SAP1, SAP2, and SAP3 genes were expressed in 50%, 100%, and 75% of the strains, respectively. The biofilm formation ability was negative in 12% of the strains, while it was considerable in 38% of the strains. Fifty percent of the strains had no phospholipase activity, and no one demonstrated high level of this pathogenesis factor. Relatively all the strains had very low potency to form pseudohyphae.
Our findings demonstrated that Candida albicans strains isolated from cutaneous candidiasis were able to cause oral and systemic infections in mice, so they could be considered as the potential agents of life-threatening nosocomial candidiasis in susceptible populations.
白色念珠菌是最重要的全球性机会性病原体之一，过去几十年中，念珠菌病的发病率有所增加。尽管皮肤在防御真菌感染方面发挥了重要作用，但关于白色念珠菌从正常菌群转变为阴道和胃肠道上皮病原体的发病机制，文献记载甚少。本研究旨在确定从皮肤病变分离出的临床白色念珠菌菌株的体内和体外发病机制。
本研究调查了不同进化起源的白色念珠菌分离株的体内和体外发病机制之间的关联。在 BALB/C 小鼠中建立了口腔和全身实验性念珠菌病。评估了白色念珠菌的分泌天冬氨酸蛋白酶（SAP1-3 基因）表达水平、形态转化和生物膜形成能力。
所有菌株均在不同程度上表现出体外和体内致病性。SAP1、SAP2 和 SAP3 基因在 50%、100%和 75%的菌株中表达。有 12%的菌株没有生物膜形成能力，而 38%的菌株则具有相当强的生物膜形成能力。50%的菌株没有磷脂酶活性，没有一个菌株表现出高水平的这种发病机制因子。相对而言，所有菌株都有很低的形成假菌丝的能力。
我们的研究结果表明，从皮肤念珠菌病分离出的白色念珠菌菌株能够在小鼠中引起口腔和全身感染，因此它们可能被认为是易感人群中危及生命的医院获得性念珠菌病的潜在病原体。
