摘要
目的:探讨远缘链球菌6715(Streptococcus sobrinus 6715,以下简称S.6715)及其耐氟菌株的适应性耐酸能力。方法:在含有不同氟浓度的TSA上逐步诱导S.6715产生耐氟突变株(以下简称S.6715-FR)。通过测定在各种酸性pH值培养基中预酸化2 h后,能否使S.6715及其耐氟突变株抵抗致死性pH杀伤而存活及存活率,来测定其适应性耐酸能力的有无及大小。结果:S.6715属强适应性耐酸能力类菌株,最大生存率9.98%出现在pH5.5预酸化组,其耐氟突变株S.6715-FR亦具有强适应性耐酸能力,最大生存率10.55%出现在pH值5.0预酸化组。结论:在亚致死性pH值中生长能引发远缘链球菌6715及其耐氟菌株的某些生理变化,产生适应性耐酸能力,抵抗酸性环境的杀伤。
Objective： To determine the acid adaptation of Streptococcus sobrinus 6715 and its fluoride - resistant strains. Methods： Fluoride -resistant strains of Streptococcus sobrinus 6715 was induced by increasing the concentration of fluoride in the TSA step by step. Adaptation to acid tolerance was measured by the ability of mid - exponential - phased cell to survive a 2 - hour exposure at killing pH. Results： Preliminary exposure of mid - exponential phase cells to a low, sub - lethal pH would enhance survival rate. The greatest viability （9.98%） of sobrinus 6715 appeared when cells were pre - acifled at pH 5.5 and the greatest viability （ 10.55% ） of fluoride - resistant strains of Streptococcus sorbrinus 6715 appeared when cells were pre - acified at pH 5. 0. Condution： Pre - acidification can trigger the introduction of some mechanisms to protect Streptococcus sobrinus 6715 and its fluoride-resistant strains from acid killing.
出处
《口腔医学研究》
CAS
CSCD
2007年第1期20-23,共4页
Journal of Oral Science Research
关键词
远缘链球菌
耐氟菌株
耐酸反应
Streptococcus sobrinus 6715 Fluoride -resistant strains Acid tolerance
