Department of Biological Chemistry, Oral Biology Department, School of Dentistry, National University of Córdoba, Argentina.
Department of Cell Biology, Histology Embryology, School of Medical Sciences, National University of Córdoba, Argentina.
Arch Oral Biol. 2017 Sep;81:74-80. doi: 10.1016/j.archoralbio.2017.04.023. Epub 2017 Apr 21.
The aim of the present work was to analyze whether the location of the dental biofilm was associated with shifts in the membrane fatty acid profile, and whether such shifts could affect certain virulence factors of strains of Streptococcus mutans.
An experimental study was conducted to assess the behavior of S. mutans strains isolated from dental biofilm collected from sound and carious smooth and occlusal surfaces of the oral cavity of children. The lipid composition of the bacterial membrane, structural membrane parameters, acid survival, and ATPase activity were tested at pH 7 and 5.
At pH 5, an increase in both the unsaturated and the long chain fatty acids as well as in proton ATPase hydrolytic activity was observed in strains isolated from carious smooth surface biofilm but not in carious occlusal surface strains. The observed changes correlated with the studied structural parameters, and were found to be associated with membrane organization. The changes correlated with a decreased in ΔC (sn-1 and sn-2 acyl chain inequivalence), indicative of increased acyl chain interaction.
The obtained results suggest that the acidic environment (pH 5) of smooth surface caries affects membrane organization, inducing a shift in membrane lipid profile, which would likely induce better protein/lipid hydrophobic matching, resulting in increased ATPase activity and higher acid survival.
本研究旨在分析牙菌斑的位置是否与膜脂肪酸谱的变化相关，以及这种变化是否会影响变形链球菌菌株的某些毒力因子。
本实验研究评估了从儿童口腔健康和龋损光滑面及咬合面牙菌斑中分离出的变形链球菌菌株的行为。在 pH 值为 7 和 5 时，测试了细菌膜的脂质组成、结构膜参数、酸存活和 ATP 酶活性。
在 pH 值为 5 时，从龋损光滑面牙菌斑中分离出的菌株中观察到不饱和和长链脂肪酸以及质子 ATP 酶水解活性的增加，但在龋损咬合面菌株中没有观察到这种增加。观察到的变化与研究的结构参数相关，与膜组织有关。这些变化与 ΔC（sn-1 和 sn-2 酰链不等价性）的减少相关，表明酰链相互作用增加。
研究结果表明，光滑面龋的酸性环境（pH 值 5）影响膜组织，诱导膜脂质谱的变化，可能会诱导更好的蛋白质/脂质疏水性匹配，从而增加 ATP 酶活性和提高酸存活能力。
