School and Hospital of Stomatology, Wenzhou Medical University, Wenzhou, China.
Center of Regenerative Medicine, Renmin Hospital of Wuhan University, Wuhan, China.
Front Cell Infect Microbiol. 2022 Feb 28;12:801569. doi: 10.3389/fcimb.2022.801569. eCollection 2022.
The widespread application of fluoride, an extremely effective caries prevention agent, induces the generation of fluoride-resistant strains of opportunistic cariogenic bacteria such as fluoride-resistant (). However, the influence of this fluoride-resistant strain on oral microecological homeostasis under fluoride remains unknown. In this study, an antagonistic dual-species biofilm model composed of and () was used to investigate the influence of fluoride-resistant on dual-species biofilm formation and pre-formed biofilms under fluoride to further elucidate whether fluoride-resistant strains would influence the anti-caries effect of fluoride from the point of biofilm control. The ratio of bacteria within dual-species biofilms was investigated using quantitative real-time PCR and fluorescence hybridization. Cristal violet staining, scanning electron microscopy imaging, and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide assay were used to evaluate biofilm biomass, biofilm structure, and metabolic activity, respectively. Biofilm acidogenicity was determined using lactic acid and pH measurements. The anthrone method and exopolysaccharide (EPS) staining were used to study the EPS production of biofilms. We found that, in biofilm formation, fluoride-resistant occupied an overwhelming advantage in dual-species biofilms under fluoride, thus showing more biofilm biomass, more robust biofilm structure, and stronger metabolic activity (except for 0.275 g/L sodium fluoride [NaF]), EPS production, and acidogenicity within dual-species biofilms. However, in pre-formed biofilms, the advantage of fluoride-resistant could not be fully highlighted for biofilm formation. Therefore, fluoride-resistant could influence the anti-caries effect of fluoride on antagonistic dual-species biofilm formation while being heavily discounted in pre-formed biofilms from the perspective of biofilm control.
氟化物的广泛应用是一种极其有效的龋齿预防剂，它会诱导机会性致龋细菌（如耐氟性（））产生耐药菌株。然而，这种耐药菌株对氟化物条件下口腔微生态平衡的影响尚不清楚。在本研究中，使用由（）和（）组成的拮抗双物种生物膜模型，研究了耐氟性（）对双物种生物膜形成和氟化物预成生物膜的影响，以进一步阐明耐氟菌株是否会从生物膜控制的角度影响氟化物的抗龋效果。使用定量实时 PCR 和荧光杂交技术研究双物种生物膜内细菌的比例。结晶紫染色、扫描电子显微镜成像和 3-（4,5-二甲基噻唑-2-基）-2,5-二苯基-2H-四唑溴化物测定法分别用于评估生物膜生物量、生物膜结构和代谢活性。生物膜产酸能力通过乳酸和 pH 值测量来确定。蒽酮法和胞外多糖（EPS）染色用于研究生物膜的 EPS 产生。我们发现，在生物膜形成过程中，耐氟性（）在氟化物条件下的双物种生物膜中占据压倒性优势，从而表现出更多的生物膜生物量、更稳健的生物膜结构和更强的代谢活性（除了 0.275 g/L 氟化钠[NaF]）、EPS 产生和双物种生物膜的产酸能力。然而，在预成生物膜中，耐氟性（）的优势无法完全凸显。因此，从生物膜控制的角度来看，耐氟性（）可以影响氟化物对拮抗双物种生物膜形成的抗龋效果，而在预成生物膜中则会被大大削弱。
