Most recent global transcription and proteomic profiling has revealed several aspects of the physiological adaptations that S. mutans undergoes following attachment to and growth on surfaces [21, 36–38]. Nevertheless, only a few comprehensive studies have compared the influence of surface materials on the gene expression of immobilized bacteria adhering to different dental biomaterials.

It is conceivable that the chemistry of the surface on which the biofilm is formed would affect the properties of the biofilm. Recent gene expression profiling showed marked differences in gene responses of bone cells on smooth and rough titanium surfaces [39]. Additional studies demonstrated that the biodegradation learn more of composite resins differentially impacts the growth and gene expression of S. mutans [40]. In addition, Selleck MK-4827 biomaterial surface chemistry affected biofilm formation, and polyethylene oxide significantly inhibited S. epidermidis biofilm formation in vitro [41]. In the current study, we have shown that gene expression differs in S. mutans biofilms formed on different surfaces, therefore likely changing the physiology and virulence of the immobilized bacteria. Our CLSM biofilm depth analysis shows that the bacteria were able to construct more confluent and thick biofilms on a hydroxyapatite surface compared

to the other surfaces tested. AI-2 is a furanone borate diester that is synthesized in many bacteria by the LuxS protein and detected in Vibrio harveyi by a periplasmic protein called LuxP. It was proposed to function as a universal quorum-sensing signal for interaction between different bacterial species [42]. It has been previously shown that the AI-2 level decreased in chemostat-grown E. coli cultures exposed to different stresses [43]. In addition, QS is likely involved in stress gene regulation in Porphyromonas gingivalis [44]. The Amoxicillin consequences

of these data may provide the potential link between the type of surface, QS and stress regulation in biofilm-grown bacteria. This might suggest that the attachment of bacteria to a particular surface may have altered the level of AI-2 signaling in the generated biofilm to overcome stressful conditions. Consistent with this hypothesis is that the levels of AI-2 in biofilms from various tested surfaces were found to be different (Figure 5). The stressful situation during the transition to a new surface apparently induces the bacteria to enhance the QS process to overcome the challenge by find more activating stress-related as well as biofilm-associated genes at the same time. Although small peptides termed competence stimulating peptides (CSP) are the main QS signaling molecules in S. mutans [45], It was shown that AI-2produced by S. mutans play a role in biofilm formation [27] and analogues of the AI-2 may affect biofilm formation of S. mutans [46]. Moreover, secretion of AI-2 of S.