Lactobacillus rhamnosus biosurfactant inhibits biofilm formation and gene expression of caries-inducing Streptococcus mutans

Abstract

Background: It is cleared that some probiotic strains inhibit biofilm formation of oral bacteria, but its mechanisms are not clearly understood yet. It is proposed that one of the mechanisms can be biosurfactant production, a structurally diverse group of surface-active compounds synthesized by microorganisms. Hence, this study focused on the evaluation of the anti-biofilm and antiadhesive activities of the L. rhamnosus derived-biosurfactant against Streptococcus mutans and its effect on gtfB/C and ftf genes expression level. Materials and Methods: In this in vitro study Lactobacillus rhamnosus ATCC7469 overnight culture was used for biosurfactant production. The biosurfactant effect on the surface tension reduction was confirmed by drop collapse method. Chemical bonds in the biosurfactant were identified by Fourier transform infrared (FTIR). Anti-biofilm and antiadhesive activities of the biosurfactant were determined on glass slides and in 96-well culture plates, respectively. The effect of the biosurfactant on gtfB/C and ftf genes expression level was also investigated after biofilm formation, total RNA extraction, and reverse transcription by quantitative real-time reverse transcriptase polymerase chain reaction (PCR) assay (quantitative PCR). The data were assessed by one-way analysis of variance in the Tukey–Kramer postdeviation test for all pairs. P < 0.05 was considered statistically significant. Results: The FTIR results of biosurfactant showed that it was protein rich. It also showed anti-biofilm formation activity on the glass slide and antiadhesive activity till 40% on microtiter plate wells. It also showed a significant reduction ( P < 0.05) in gtfB/C and ftf genes expression level. Conclusion: L. rhamnosus -derived biosurfactant exhibits a significant inhibitory effect on biofilm formation ability of S. mutans due to downregulation of biofilm formation associated genes, gtfB/C and ftf . L. rhamnosus -derived biosurfactant with substantial antiadhesive activity is suitable candidates for use in new generations of microbial antiadhesive agents.

Effects of Probiotic Culture Supernatant on Cariogenic Biofilm Formation and RANKL-Induced Osteoclastogenesis in RAW 264.7 Macrophages

“…Surface-active protein-rich biosurfactants derived from lactobacilli possibly decrease surface tension and inhibit biofilm formation [ 34 , 35 ].…”

Suppressive Effects of Hainosan (Painongsan) against Biofilm Production by Streptococcus mutans

“…The less extracellular polysaccharides are generated, the lower the cariogenicity of S. mutans [27]. Thus, most researchers are interested in the production and gene regulation of virulence factors, such as gtfs, which are associated with S. mutans biofilm, to control tooth decay [23,24]. Although the inhibition of essential virulence factors (gtf and ftf) may be the principal purpose for the prevention of tooth decay and other plaque-related disorders, among the many crude drugs used in traditional Chinese medicine and Kampo medicine, we cannot find any crude drugs that affect glucosyltransferase of S. mutans including the suppression of mRNA expression except for those constituting hainosan.…”

“…These S. mutans-secreted glucosyltransferases make specific binding sites useful for the bacterial colonization of the tooth surface as the precursor of dental caries [23]. As the product of the ftf gene possesses the function as extracellular storage polysaccharides, it presents a characteristic microenvironment for bacterial life [24]. Thus, the suppression of these polysaccharide synthesis by influencing these encoding genes expression is an effective approach to abrogate the plaque formation and dental caries [24].…”

“…As the product of the ftf gene possesses the function as extracellular storage polysaccharides, it presents a characteristic microenvironment for bacterial life [24]. Thus, the suppression of these polysaccharide synthesis by influencing these encoding genes expression is an effective approach to abrogate the plaque formation and dental caries [24]. As previous studies have shown that the gtfB, gtfC, and ftf genes are critical for the sucrose-dependent adhesion of S. mutans to hard surfaces, gtfD is not essential [25].…”

Increase in bacterial biosurfactant production by co‐cultivation with biofilm‐forming bacteria

“…As an antimicrobial response, BSF production is induced or stimulated in microbial consortia involving pathogenic partners (Dusane et al 2011;Hamza et al 2018) and underlies cross-species antifouling effects (Tahmourespour et al 2019). Within this framework, we hypothesized that co-cultivation of environmental BSFproducing isolates of Bacillus licheniformis and Pseudomonas sp.…”