Relationship between the probiotic Lactobacillus rhamnosus and Enterococcus faecalis during the biofilm formation

One of the factors that make the treatment of Enterococcus faecalis infections difficult is their ability to form biofilm, as well as their natural and acquired resistance to antibiotics which does not have specific drugs for their inhibition. This fact makes essential the search for alternative treatments, as the use of probiotics strains of Lactobacillus rhamnosus has been effective in the treatment of some diseases. In this investigation, the relationship between the probiotic strain of L. rhamnosus and E. faecalis during the biofilm formation was analyzed. Standardized suspensions used in biofilm development and treatment in different stages of the biofilm formation were prepared. The L. rhamnosus suspension was placed in contact for 90 min with E. faecalis freshly created biofilms (initial adherence) in the 24 h biofilms. The same was made with E. faecalis suspension on L. rhamnosus biofilms. L. rhamnosus showed no inhibitory effects on E. faecalis biofilms formation, with an increase in the counting of colony forming units in the treated groups (p=0.0047, p=0.0060).  About the L. rhamnosus biofilms, there was no significant difference for both treatment stages. The probiotic strain interfered in vitro with the E. faecalis biofilm formation, thereby intensifying the growth of E. faecalis biofilm. Key words: Enterococcus faecalis, Lactobacillus rhamnosus, biofilm, virulence factor, probiotic.