IADR Abstract Archives
COMMUNICATION BETWEEN TWO CARIOGENIC MICROORGANISMS: BIFIDOBACTERIUM DENTIUM AND LACTOBACILLUS CASEI
Objectives: To analyze the effect of Bifidobacterium dentium, by cellular communication mediated by the autoinducer-2 molecule, in the adhesion and biofilm formation of Lactobacillus casei.
Methods: Protocol approved by the Institutional Biosafety Committee and by the Scientific Ethics Committee of the Faculty of Dentistry, University of Chile. L. casei ATCC 4646 and B. dentium ATCC 27534 strains, obtained from caries sites, were used. For all the analyzes both strains were cultured in MRS medium in anaerobiosis at 37 °C. The presence and functionality of autoinducer-2 (AI-2) produced by B. dentium was detected by means of an assay with the Vibrio harveyi BAA-1117TM reporter strain, which produces luminescence in the presence of this molecule. The MTT (Sigma®) test was used for the adhesion test. For biofilm formation analysis, glass coverslips embedded in saliva were used, under static conditions, and the results were visualized using Scanning Electron Microscopy. In both assays, L. casei was analyzed in the presence and absence of AI-2 of the supernatant of B. dentium culture and AI-2 chemically synthesized as a control.
Results: Significant amounts of AI-2 were detected in the stationary phase culture of B. dentium. This molecule is capable of generating an increase in the adhesion and biofilm formation of L. casei ATCC 4646, which presents low adherence and biofilm formation in the absence of it.
Conclusions: B. dentium is able to enhance the adhesion and initial formation of L. generating biofilm, through the production and secretion of AI-2 to the external environment. These results indicate that cellular communication mediated by AI-2 can generate positive effects among cariogenic microorganisms. These findings are very useful to understand the nature of the interaction between these microorganisms, as well as the mechanisms of fundamental processes for pathogenicity, such as adhesion to surfaces and the biofilm formation.
Methods: Protocol approved by the Institutional Biosafety Committee and by the Scientific Ethics Committee of the Faculty of Dentistry, University of Chile. L. casei ATCC 4646 and B. dentium ATCC 27534 strains, obtained from caries sites, were used. For all the analyzes both strains were cultured in MRS medium in anaerobiosis at 37 °C. The presence and functionality of autoinducer-2 (AI-2) produced by B. dentium was detected by means of an assay with the Vibrio harveyi BAA-1117TM reporter strain, which produces luminescence in the presence of this molecule. The MTT (Sigma®) test was used for the adhesion test. For biofilm formation analysis, glass coverslips embedded in saliva were used, under static conditions, and the results were visualized using Scanning Electron Microscopy. In both assays, L. casei was analyzed in the presence and absence of AI-2 of the supernatant of B. dentium culture and AI-2 chemically synthesized as a control.
Results: Significant amounts of AI-2 were detected in the stationary phase culture of B. dentium. This molecule is capable of generating an increase in the adhesion and biofilm formation of L. casei ATCC 4646, which presents low adherence and biofilm formation in the absence of it.
Conclusions: B. dentium is able to enhance the adhesion and initial formation of L. generating biofilm, through the production and secretion of AI-2 to the external environment. These results indicate that cellular communication mediated by AI-2 can generate positive effects among cariogenic microorganisms. These findings are very useful to understand the nature of the interaction between these microorganisms, as well as the mechanisms of fundamental processes for pathogenicity, such as adhesion to surfaces and the biofilm formation.