Ceresa C, Tessarolo F, Caola I, Nollo G, Cavallo M, Rinaldi M, Fracchia L
Department of Pharmaceutical Sciences, Università del Piemonte Orientale "A. Avogadro", Novara, Italy.
J Appl Microbiol. 2015 May;118(5):1116-25. doi: 10.1111/jam.12760. Epub 2015 Feb 28.
The study aimed at investigating the ability of biosurfactant (BS) produced by a Lactobacillus brevis isolate (CV8LAC) to inhibit adhesion and biofilm formation of Candida albicans on medical-grade silicone elastomeric disks (SEDs).
Biosurfactant activity was evaluated at physiological conditions, by means of co-incubation and precoating assays. Additionally, BS extract was tested for antifungal susceptibility against C. albicans in both planktonic and sessile form. Biofilm covered surface and hyphae and blastospores occurrence were quantified by scanning electron microscopy (SEM) and image analysis. BS did not inhibit growth of C. albicans in both planktonic and sessile form. Nevertheless, co-incubation with 2000 μg ml(-1) BS significantly reduced biofilm formation on SEDs surface by 89, 90 and 90% after 24, 48 and 72 h of incubation. Fungal adhesion and biofilm formation to precoated SEDs was reduced by 62, 53, 50 and 44% after 1.5, 24, 48 and 72 h. SEM showed a significant reduction of biofilm covered surface in precoated disks but no differences in the production of hyphae or blastospores, except at 1.5 h of incubation.
This study demonstrated that CV8LAC BS has the ability to counteract significantly the initial deposition of C. albicans to silicone surfaces and to effectively slow biofilm growth.
The anti-adhesive properties of the CV8LAC BS suggest a potential role of the coating for preventing fungal infection associated to silicone medical devices.
本研究旨在调查短乳杆菌分离株（CV8LAC）产生的生物表面活性剂（BS）抑制白色念珠菌在医用级硅橡胶弹性体圆盘（SEDs）上黏附及生物膜形成的能力。
通过共孵育和预包被试验在生理条件下评估生物表面活性剂活性。此外，对BS提取物针对浮游态和固着态白色念珠菌的抗真菌敏感性进行了测试。通过扫描电子显微镜（SEM）和图像分析对生物膜覆盖的表面以及菌丝和芽生孢子的出现情况进行了定量。BS对浮游态和固着态白色念珠菌的生长均无抑制作用。然而，与2000μg/ml BS共孵育后，在孵育24、48和72小时后，SEDs表面的生物膜形成分别显著减少了89%、90%和90%。在1.5、24、48和72小时后，真菌对预包被SEDs的黏附和生物膜形成分别减少了62%、53%、50%和44%。SEM显示预包被圆盘中生物膜覆盖的表面显著减少，但除孵育1.5小时外，菌丝或芽生孢子的产生没有差异。
本研究表明CV8LAC BS有能力显著对抗白色念珠菌在硅橡胶表面的初始沉积，并有效减缓生物膜生长。
CV8LAC BS的抗黏附特性表明其在预防与硅橡胶医疗器械相关的真菌感染方面具有潜在作用。
