Parga Ana, Balboa Sabela, Otero-Casal Paz, Otero Ana
Department of Microbiology and Parasitology, CIBUS-Faculty of Biology, Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Spain.
Department of Microbiology and Parasitology, Center of Cross-Disciplinary Research in Environmental Technologies (CRETUS), Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Spain.
Antibiotics (Basel). 2023 Jul 31;12(8):1263. doi: 10.3390/antibiotics12081263.
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 and . Both and 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.
群体淬灭（QQ）是对细菌通讯即群体感应（QS）的抑制。群体感应是调节复杂细菌群落（如在致龋生物膜中发现的群落）中生物膜形成和表型的关键机制。虽然群体淬灭方法已被证明能有效减少生物量，但关于它们对口腔多微生物生物膜分类组成的影响的了解仍然很少。在这里，我们研究了群体淬灭内酯酶Aii20J对生物膜生物量产生和分类组成的影响。我们从10名无龋儿童和10名患龋儿童中收集龈上菌斑样本，并将其培养以生成体外生物膜。通过结晶紫测定法评估，我们发现暴露于Aii20J后生物量显著减少。使用16S rRNA基因扩增子测序进行的分类分析显示，在属水平上细菌组成没有显著变化。有趣的是，在种水平上，Aii20J处理增加了[具体物种1]和[具体物种2]的丰度。[具体物种1]和[具体物种2]都表达pH缓冲酶（分别为精氨酸脱亚氨酶和脲酶），它们催化氨的产生，从而可能提高局部pH值并抵消生物膜的致龋潜力。在本研究的局限性范围内，我们的发现提供了群体淬灭对生物膜调节能力的证据，并为恢复生态失调生态系统内的稳态的替代策略提供了新的见解。
