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BioMed Research International
Volume 2013 (2013), Article ID 431465, 8 pages
http://dx.doi.org/10.1155/2013/431465
Research Article

Fibrinogen-Induced Streptococcus mutans Biofilm Formation and Adherence to Endothelial Cells

1Department of Oral Diagnosis and Surgery, Araraquara Dental School, State University of São Paulo, 14801-903 Araraquara, SP, Brazil
2Oral Ecology Research Group, Faculty of Dentistry, Laval University, 2420 Rue de la Terrasse, Quebec City, QC, Canada G1V 0A6
3Department of Physiology and Pathology, Araraquara Dental School, State University of São Paulo, 14801-903 Araraquara, SP, Brazil

Received 13 May 2013; Revised 20 August 2013; Accepted 30 August 2013

Academic Editor: Edouard Tuaillon

Copyright © 2013 Telma Blanca Lombardo Bedran et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Streptococcus mutans, the predominant bacterial species associated with dental caries, can enter the bloodstream and cause infective endocarditis. The aim of this study was to investigate S. mutans biofilm formation and adherence to endothelial cells induced by human fibrinogen. The putative mechanism by which biofilm formation is induced as well as the impact of fibrinogen on S. mutans resistance to penicillin was also evaluated. Bovine plasma dose dependently induced biofilm formation by S. mutans. Of the various plasma proteins tested, only fibrinogen promoted the formation of biofilm in a dose-dependent manner. Scanning electron microscopy observations revealed the presence of complex aggregates of bacterial cells firmly attached to the polystyrene support. S. mutans in biofilms induced by the presence of fibrinogen was markedly resistant to the bactericidal effect of penicillin. Fibrinogen also significantly increased the adherence of S. mutans to endothelial cells. Neither S. mutans cells nor culture supernatants converted fibrinogen into fibrin. However, fibrinogen is specifically bound to the cell surface of S. mutans and may act as a bridging molecule to mediate biofilm formation. In conclusion, our study identified a new mechanism promoting S. mutans biofilm formation and adherence to endothelial cells which may contribute to infective endocarditis.