龋病相关牙菌斑4种主要细菌的体外耐酸能力分析

Aciduricity analysis of 4 predominant species associated with caries in vitro

目的分析龋病相关牙菌斑4种摘要细菌,变链菌、血链菌、放线菌和乳杆菌的体外耐酸能力。方法采用96孔微量板液体培养法观察不同pH条件下,单一或复合培养细菌的生长情况。结果单一培养细菌,乳杆菌的最低耐受pH为2.0～3.0,变链菌的最低耐受pH为3.0～4.0,血链菌最低耐受pH为4.0～5.0,放线菌的最低耐受pH为5.0～6.0。与乳杆菌共培养,变链菌或放线菌的pH耐受均降低。放线菌与血链菌(19246-10556)混合培养,观察到二者依pH变化的比例反转。结论牙菌斑各主要细菌具有不同的耐酸性,这种耐酸性可能与牙菌斑细菌的继承和龋病的进程相关。乳杆菌在低pH条件下对其他共同生长细菌的抑制,可能有乳杆菌素的作用。

Objective To analyze the aciduricity of Streptococcus mutans,Streptococcus sanguis,Actinomyces and Lactobacillus in vitro.Methods The bacterial growth of alone or co-culture was observed through liquid culture on a 96-well microtiter plate under different pH conditions.Results The minimum aciduricity of Lactobacillus,S.mutans,Streptococcus sanguis and Actinomycetes were pH 2.0 to 3.0,pH 3.0 to 4.0,pH 4.0 to 5.0 and pH 5.0 to 6.0 repectively in the condition of alone culture.Streptococcus bacteria or Actinomycetes showed lower pH tolerance when co-cultured with Lactobacillus.The reversal changes of aciduriccity were observed in the mixed culture of Actinomycetes and Streptococcus sanguis from pH 7.0 to pH 2.0.Conclusion Different aciduricity of bacteria may be associated with the success of bacteria in plaque and caries process.Lactobacillus bacteriocin may play a role in the growth inhibition of the bacteria co-cultured with Lactobacillus under low pH conditions.