Inhibition of<i>Steptococcus mutans</i>biofilm formation by extracts of<i>Tenacibaculum</i>sp. 20J, a bacterium with wide-spectrum quorum quenching activity

Abstract

<b>Background</b>: Previous studies have suggested the quorum sensing signal AI-2 as a potential target to prevent the biofilm formation by <i>Streptococcus mutans</i>, a pathogen involved in tooth decay. <b>Objective</b>: To obtain inhibition of biofilm formation by <i>S. mutans</i> by extracts obtained from the marine bacterium <i>Tenacibaculum</i> sp. 20J interfering with the AI-2 quorum sensing system. <b>Design</b>: The AI-2 inhibitory activity was tested with the biosensors <i>Vibrio harveyi</i> BB170 and JMH597. <i>S. mutans</i> ATCC25175 biofilm formation was monitored using impedance real-time measurements with the xCELLigence system®, confocal laser microscopy, and the crystal violet quantification method. <b>Results</b>: The addition of the cell extract from <i>Tenacibaculum</i> sp. 20J reduced biofilm formation in <i>S. mutans</i> ATCC25175 by 40-50% compared to the control without significantly affecting growth. A decrease of almost 40% was also observed in <i>S. oralis</i> DSM20627 and <i>S. dentisani</i> 7747 biofilms. <b>Conclusions</b>: The ability of <i>Tenacibaculum</i> sp. 20J to interfere with AI-2 and inhibit biofilm formation in <i>S. mutans</i> was demonstrated. The results indicate that the inhibition of quorum sensing processes may constitute a suitable strategy for inhibiting dental plaque formation, although additional experiments using mixed biofilm models would be required.