GLYCEROL MONOLAURATE INHIBITS INDUCTION OF VANCOMYCIN RESISTANCE IN ENTEROCOCCUS-FAECALIS

Glycerol monolaurate (GML) is a surfactant that has been found to inhi bit the post-exponential phase activation of virulence factor producti on and the induction of beta-lactamase in Staphylococcus aureus, It ha s been suggested. that signal transduction is the most probable target for GML (S. J. Projan, S. Brown-Skrobot, P. M. Schlievert, F. Vandene sch, and R. P. Novick, J. Bacteriol. 176:4204-4209, 1994). We found th at GML suppresses growth of vancomycin-resistant Enterococcus faecalis on plates with vancomycin and blacks the induction of vancomycin resi stance, which involves a membrane-associated signal transduction mecha nism, either at or before initiation of transcription, Given the surfa ctant nature of GML and the results of previous experiments, vie sugge st that GML blacks signal transduction. In contrast, GML has no effect on the induction of erythromycin-inducible macrolide resistance in S. aureus, which does not involve signal transduction.