Velraeds M M, van der Mei H C, Reid G, Busscher H J
Laboratory for Materia Technica, University of Groningen, The Netherlands.
Urology. 1997 May;49(5):790-4. doi: 10.1016/S0090-4295(97)00065-4.
The potency of the Lactobacillus acidophilus RC14 biosurfactant "surlactin" to reduce the initial adhesion of Enterococcus faecalis 1131 was investigated on a hydrophilic and a hydrophobic substratum in a parallel-plate flow chamber, using phosphate-buffered saline and pooled human urine as a suspending fluid.
A parallel-plate flow chamber with a glass or silicone rubber bottom plate was filled with different biosurfactant solutions of 0, 0.01, 0.1, or 1.0 mg/mL for overnight adsorption (18 hours). Subsequently, the adhesion of E. faecalis on thus prepared biosurfactant layers was observed in situ in phosphate-buffered saline or in urine by automated image analysis.
Adsorbed biosurfactant layers caused an important, dose-related inhibition of the initial deposition rate of E. faecalis and the number of adherent bacteria after 4 hours on both hydrophilic glass and hydrophobic silicone rubber, although this effect was stronger in buffer than in urine. For the experiments carried out in urine, the inhibitory effect of the biosurfactant layer was largest when silicone rubber was used rather than glass, whereas no influence of the substratum hydrophobicity on the inhibition of E. faecalis adhesion was noticed for experiments performed in buffer.
The biosurfactant surlactin, as released by several Lactobacillus isolates, might open the way to the development of antiadhesive biologic coatings for catheter materials. It should be considered, however, that these results are preliminary and that the efficiency of the biosurfactant is probably affected not only by the hydrophobicity of the substratum and the suspending fluid, but also by the type of uropathogen involved.
在平行平板流动腔中，以磷酸盐缓冲盐水和混合人尿作为悬浮液，研究嗜酸乳杆菌RC14生物表面活性剂“表面活性素”降低粪肠球菌1131初始黏附的能力，实验分别在亲水性和疏水性基质上进行。
在底部为玻璃或硅橡胶的平行平板流动腔中，加入浓度分别为0、0.01、0.1或1.0 mg/mL的不同生物表面活性剂溶液，放置过夜（18小时）使其吸附。随后，通过自动图像分析原位观察粪肠球菌在如此制备的生物表面活性剂层上在磷酸盐缓冲盐水中或尿液中的黏附情况。
吸附的生物表面活性剂层对粪肠球菌的初始沉积速率和4小时后黏附细菌数量产生了重要的、与剂量相关的抑制作用，在亲水性玻璃和疏水性硅橡胶上均如此，不过这种作用在缓冲液中比在尿液中更强。对于在尿液中进行的实验，当使用硅橡胶而非玻璃时，生物表面活性剂层的抑制作用最大，而在缓冲液中进行的实验未观察到基质疏水性对粪肠球菌黏附抑制的影响。
几种乳酸杆菌分离株释放的生物表面活性剂表面活性素可能为开发用于导管材料的抗黏附生物涂层开辟道路。然而，应该考虑到这些结果是初步的，并且生物表面活性剂的效率可能不仅受到基质和悬浮液疏水性的影响，还受到所涉及的尿路病原体类型的影响。
