Inhibition of initial adhesion of uropathogenic Enterococcus faecalis to solid substrata by an adsorbed biosurfactant layer from Lactobacillus acidophilus

• Published in: Urology (Ridgewood, N.J.) Vol. 49; no. 5; pp. 790 - 794
• Main Authors: Velraeds, Martine M.C., Van Der Mei, Henny C., Reid, Gregor, Busscher, Henk J.
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Inc 01.05.1997; Elsevier Science
• Subjects: Bacterial Adhesion; Bacterial diseases; Bacterial diseases of the urinary system; Bacterial Proteins - biosynthesis; Bacterial Proteins - physiology; Biological and medical sciences; Enterococcus faecalis - physiology; Human bacterial diseases; Infectious diseases; Lactobacillus acidophilus - metabolism; Medical sciences; Surface-Active Agents; Enterococcus faecalis; Urinary system disease; Secretion; Experimental study; Lactobacillus acidophilus; Adhesion; In vitro; Infection; Streptococcaceae; Urinary system; Bacteriosis; Bacteria; Lactobacillaceae; Micrococcales; Biological effect
• ISSN: 0090-4295; 1527-9995
• 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, how-ever, 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.