Background

Invasive candidiasis by Candida albicans is associated with high morbidity and mortality, due in part to the late implementation of an appropriate antifungal therapy hindered by the lack of an early diagnosis.

Aims

We aimed to evaluate the in vitro antifungal activity of the antibodies against C. albicans germ tubes (CAGTA) raised in a rabbit model of candidemia.

Methods

We measured the effect of CAGTA activity by colorimetric XTT and crystal violet assays, and colony forming units count, both on C. albicans planktonic cells and during the course of biofilm formation and maturation. Viability and cell morphology were assessed by optical, fluorescent or scanning electron microscopy.

Results

CAGTA ≥50 μg/ml caused a strong inhibition of C. albicans blastospores growth, and DiBAC fluorescent staining evidenced a fungicidal activity. Moreover, electron microscopy images revealed that CAGTA induced morphological alterations of the surface of C. albicans germ tubes grown free as well as in biofilm. Interestingly, CAGTA ≥80 μg/ml reduced the amount of C. albicans biofilm, and this effect started at the initial adhesion stage of the biofilm formation, during the first 90 min.

Conclusions

This is the first report showing that CAGTA reduce C. albicans growth, and impair its metabolic activity and ability to form biofilm in vitro. The antigens recognized by CAGTA could be the basis for the development of immunization protocols that might protect against Candida infections.

中文翻译：

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抗白色念珠菌种管抗体可降低白色念珠菌的体外生长和生物膜形成。

背景

白色念珠菌侵袭性念珠菌病与高发病率和高死亡率相关，部分原因是由于缺乏早期诊断而阻碍了适当的抗真菌治疗的实施。

目的

我们旨在评估在兔念珠菌血症模型中产生的针对白色念珠菌种管（CAGTA）的抗体的体外抗真菌活性。

方法

我们通过比色XTT和结晶紫测定法测量了CAGTA活性对白色念珠菌浮游细胞以及生物膜形成和成熟过程的影响以及菌落形成单位计数。通过光学，荧光或扫描电子显微镜评估生存力和细胞形态。

结果

CAGTA≥50μg/ ml强烈抑制白色念珠菌芽孢的生长，DiBAC荧光染色证明具有杀菌活性。此外，电子显微镜图像显示，CAGTA诱导了自由生长以及在生物膜中生长的白色念珠菌胚管表面的形态变化。有趣的是，≥80μg/ ml的CAGTA减少了白色念珠菌生物膜的量，并且这种作用始于生物膜形成的最初粘附阶段，即前90分钟。

结论

这是第一个报告，表明CAGTA降低了白色念珠菌的生长，并削弱了其代谢活性和体外形成生物膜的能力。CAGTA识别的抗原可能是开发可预防念珠菌感染的免疫方案的基础。