New Preventive Strategy against Oral Biofilm Formation in Caries-Active Children: An In Vitro Study

Abstract

Quorum quenching (QQ) is the inhibition of bacterial communication, i.e., quorum sensing (QS). QS is a key mechanism in regulating biofilm formation and phenotype in complex bacterial communities, such as those found within cariogenic biofilms. Whereas QQ approaches were shown to effectively reduce biomass, knowledge of their impact on the taxonomic composition of oral polymicrobial biofilms remains scarce. Here, we investigate the effect of the QQ lactonase Aii20J on biomass production and taxonomical composition of biofilms. We collected supragingival plaque samples from 10 caries-free and 10 caries-active children and cultured them to generate in vitro biofilms. We describe significant biomass reductions upon Aii20J exposure, as assessed by crystal violet assays. Taxonomical profiling using 16S rRNA gene amplicon sequencing revealed no significant changes in bacterial composition at the genus level. Interestingly, at the species level Aii20J-treatment increased the abundance of Streptococcus cristatus and Streptococcus salivarius. Both S. cristatus and S. salivarius express pH-buffering enzymes (arginine deiminase and urease, respectively) that catalyze ammonia production, thereby potentially raising local pH and counteracting the biofilm’s cariogenic potential. Within the limitations of the study, our findings provide evidence of the biofilm-modulating ability of QQ and offer novel insights into alternative strategies to restore homeostasis within dysbiotic ecosystems.

N-acyl homoserine lactone signaling modulates bacterial community associated with human dental plaque

“…Interestingly, this work reveals that AHL signaling affects critical microbes for plaque establishment and oral health. For instance, AHL signal disruption in 5% CO 2 cultures favors Streptococcus, a finding that resonates with previous reports [111,112].…”

N -acyl homoserine lactones lactonase est816 suppresses biofilm formation and periodontitis in rats mediated by Aggregatibacter actinomycetemcomitans

“…Exogenous AHLs and their analogs were previously shown to affected biofilm formation and slowed Porphyromonas gingivalis growth, which highlighted the critical role of AHLs-mediated QS in oral microbiota and biofilm formation [ 8 ]. Furthermore, exogenous AHLs promoted biofilm formation and regulated the transcriptional network involved in virulence and stress tolerance in Enterococcus faecalis strains, which raised an insight into the Gram-positive bacteria among oral polymicrobial communities [ 9 ]. Therefore, suppression of AHLs as a treatment target may be a promising adjuvant treatment strategy for biofilm-associated oral infectious diseases.…”

Do Concurrent Peri-Implantitis and Periodontitis Share Their Microbiotas? A Pilot Study

“…A genomic DNA (gDNA) extraction was performed using the "DNeasy PowerBiofilm Kit" (Qiagen ® ) following the manufacturer's instructions (https://www.qiagen.com, accessed on 7 April 2024). This kit has previously provided good recovery rates in oral biofilms, even in those dominated by Gram-positive species [31] and in supragingival biofilm samples with adequate recovery of Gram-positive members [32]. Briefly, samples were mechanically analysed before removing protein and inhibitor contaminants.…”

“…The paired-end fastq files were processed as described elsewhere [31,32] using the prinseq-lite program [35] and the DADA2 pipeline [36]. Trimming and filtering of lowquality bases was performed.…”