Kara Duygu, Luppens Suzanne B I, Cate Jacob M
Academic Center for Dentistry Amsterdam, Department of Cariology, Endodontology and Pedodontology, Amsterdam, the Netherlands.
Eur J Oral Sci. 2006 Feb;114(1):58-63. doi: 10.1111/j.1600-0722.2006.00262.x.
Streptococcus mutans, considered a primary pathogen in dental caries, thrives in dental plaque, which is a multispecies biofilm. Metabolic interactions between S. mutans and Veillonella parvula have been suggested. In this study we developed a biofilm model to quantify single-species (S. mutans or V. parvula) and dual-species (S. mutans and V. parvula) biofilm formation, and we identified the differences between the respective biofilms in terms of growth, acid formation, and response to chlorhexidine. Polystyrene 96-well microtiter plates were used for biofilm formation. These biofilms were exposed to various chlorhexidine concentrations (0.025-0.4 mg ml(-1)) and treatment conditions. Growth of the biofilms and the effects of chlorhexidine were evaluated by viable counts. Viability of the two species in all biofilm types was similar ( approximately 10(8) colony-forming units per well) after 72 h. Lactic acid accumulation of dual-species biofilms was significantly lower at 48 and 72 h than single-species biofilms of S. mutans. Dual-species biofilms were less susceptible to chlorhexidine than single-species biofilms when a neutralization step was included. These results indicate that bacteria in dual-species biofilms have different properties from bacteria in single-species biofilms.
变形链球菌被认为是龋齿的主要致病菌，它在牙菌斑（一种多物种生物膜）中大量繁殖。有研究表明变形链球菌与小韦荣球菌之间存在代谢相互作用。在本研究中，我们建立了一个生物膜模型，以量化单物种（变形链球菌或小韦荣球菌）和双物种（变形链球菌和小韦荣球菌）生物膜的形成，并确定各自生物膜在生长、酸形成以及对氯己定的反应方面的差异。使用聚苯乙烯96孔微量滴定板进行生物膜形成。将这些生物膜暴露于不同的氯己定浓度（0.025 - 0.4 mg ml(-1)）和处理条件下。通过活菌计数评估生物膜的生长以及氯己定的作用。72小时后，所有生物膜类型中两种细菌的活力相似（每孔约10(8)个菌落形成单位）。在48小时和72小时时，双物种生物膜的乳酸积累量明显低于变形链球菌的单物种生物膜。当包含中和步骤时，双物种生物膜比单物种生物膜对氯己定的敏感性更低。这些结果表明，双物种生物膜中的细菌与单物种生物膜中的细菌具有不同的特性。
