不同pH值对变异链球菌ffh基因表达的影响

目的 检测变异链球菌（S. mutans）ffh基因在不同pH值条件下的表达水平，分析pH值对S. mutans ffh基因表达的影响，分析调控ffh表达的因素。方法 在不同培养时段（4 h和18 h）和不同pH值（pH值4.0~7.0）条件下培养S. mutans标准菌株UA159，提取样本，用荧光定量聚合酶链反应（qRT-PCR）法检测样本中目的基因ffh的mRNA转录水平的变化情况，分析S. mutans ffh基因在不同培养时段和pH值条件下的表达变化趋势。结果 培养4 h时，ffh基因相对表达量随着pH值的降低而减少，培养18 h时，ffh基因相对表达量随着pH值的降低而增加；相同pH值条件下，ffh基因相对表达量在培养4 h与18 h时的差异有统计学意义（P<0.05）。结论 S. mutans ffh基因的表达受细菌培养时段和pH值的影响。

Effects of different pH conditions on ffh gene expression in Streptococcus mutans

Objective This research aimed to detect the expression levels of ffh gene in Streptococcus mutans (S. mutans) UA159 under different pH conditions, analyze the effect of pH on the expression of ffh gene in S. mutans, and identify the factors regulating the ffh gene expression. Methods Samples of S. mutans were collected at different growth stages (4 h, 18 h) and pH values (pH 4.0–7.0). Fluorescence quantitative real-time polymerase chain reaction (qRT-PCR) was used to measure the relative mRNA expression and trend of the target gene ffh in S. mutans at different growth stages and pH values. Results qRT-PCR results showed that the ffh gene expression decreased along with pH at 4 h, but the expression increased with decreasing pH at 18 h. Under the same pH conditions, the ffh gene expression was significantly different between 4 h and 18 h (P<0.05). Conclusion Growth stage and pH value influenced the ffh gene expression in S. mutans.