Department of Immunology, Microbiology and Parasitology, Faculty of Pharmacy, University of the Basque Country UPV/EHU, Vitoria-Gasteiz, Araba, Spain.
Department of Nursing I, Faculty of Medicine and Nursing, University of the Basque Country UPV/EHU, Leioa, Bizkaia, Spain.
Mycopathologia. 2024 Feb 7;189(1):16. doi: 10.1007/s11046-023-00819-w.
Invasive candidiasis (IC), caused by Candida yeasts, particularly Candida albicans, poses a significant threat with high mortality rates. Diagnosis is challenging due to Candida's common presence in human microbiota. To address this, our research group developed an immunofluorescence assay detecting Candida albicans Germ Tube Antibodies (CAGTA) in IC patients. CAGTA, indicative of invasive processes, is associated with a lower mortality rate in ICU patients. Based on this premise, this study aims to provide results regarding the lack of knowledge about the potential activity of CAGTA against invasive infections in humans caused by the fungus Candida albicans. Therefore, in order to characterize the activity of CAGTA produced by patients with IC, we used sera from 29 patients with IC caused by either C. albicans or non-albicans Candida species. Whole serum IgG antibodies were fractionated into anti-blastospores, CAGTA-enriched, and purified CAGTA and the assessments included XTT colorimetric assays for metabolic activity, CFU counts for viability, and microscopy for growth, viability, and morphological analysis. The CAGTA-enriched IgG fraction significantly reduced the metabolic activity and viability of C. albicans compared to anti-blastospores. Purified CAGTA altered germ tube cell wall surfaces, as revealed by electron microscopy, and exhibited fungicidal properties by DiBAC fluorescent staining. In conclusion, antibodies in response to invasive candidiasis have antifungal activity against Candida albicans, influencing metabolic activity, viability, and cell wall structure, leading to cell death. These findings suggest the potential utility of CAGTA as diagnostic markers and support the possibility of developing immunization protocols against Candida infections.
侵袭性念珠菌病（IC）由念珠菌属酵母引起，尤其是白色念珠菌，死亡率高，威胁极大。由于念珠菌在人类微生物群中很常见，因此诊断具有挑战性。为了解决这个问题，我们的研究小组开发了一种免疫荧光检测法，用于检测 IC 患者的白色念珠菌芽管抗体（CAGTA）。CAGTA 是侵袭过程的指标，与 ICU 患者的低死亡率相关。基于这一前提，本研究旨在提供有关缺乏对白色念珠菌引起的人类侵袭性感染中 CAGTA 潜在活性的认识的结果。因此，为了表征 IC 患者产生的 CAGTA 的活性，我们使用了 29 例由白色念珠菌或非白色念珠菌念珠菌引起的 IC 患者的血清。将全血清 IgG 抗体分为抗芽生孢子、CAGTA 富集和纯化 CAGTA，评估包括 XTT 比色法测定代谢活性、CFU 计数测定活力以及显微镜观察生长、活力和形态分析。与抗芽生孢子相比，CAGTA 富集 IgG 部分显著降低了白色念珠菌的代谢活性和活力。电子显微镜显示，纯化的 CAGTA 改变了芽管细胞壁表面，并通过 DiBAC 荧光染色表现出杀菌特性。总之，针对侵袭性念珠菌病的抗体对白色念珠菌具有抗真菌活性，影响代谢活性、活力和细胞壁结构，导致细胞死亡。这些发现表明 CAGTA 作为诊断标志物的潜在用途，并支持开发针对念珠菌感染的免疫接种方案的可能性。
