LuxS基因突变对变形链球菌产酸代谢的影响

Effect of LuxS mutation on the acid production of Streptococcus mutans

目的:研究LuxS基因突变对变形链球菌产酸代谢的影响,以探讨变形链球菌LuxS基因缺陷菌株致龋毒力的变化。方法:采用比浊法测定不同培养条件下变形链球菌LuxS基因缺陷菌株培养液的吸光度A值;同时测定不同培养条件下培养基上清液的pH值。结果:基因缺陷株细菌A值显著低于标准株(P<0.05);培养基初始pH>5.0时,其产酸量小于亲代株,差异有统计学意义(P<0.05)。结论:变形链球菌LuxS基因缺陷菌株的产酸代谢能力下降,其致龋力小于亲代菌株。

AIM： To study the effect of LuxS mutation on the acid production of Streptococcus mutans in vitro, and find out the differences of cariogenicity between LuxS mutant strain and Streptococcus mutans Ingbritt C international standard strain. METHODS ： Nepbelometer method was used to measure A value of the supernatant of Streptococcus mutans LuxS in the different incubation conditions for 4h. At the same time, the pH values of glycolysis media in the different treatment conditions were measured. RESULTS ： The A value of Streptococcus mutans LuxS mutant was lower than that of the standard strain, and there was significant statistical difference between them （ P 〈 0.05 ）. The acid production of LuxS mutant was less than that of the standard strain at initial pH above 5.0 （ P 〈 0.05 ） while the result has no significant difference when pH was 5.0 and below. CONCLUSION ： LuxS mutation can inhibit the acid production of Streptococcus mutans which has a weaker cariogenic potential than its parent strain .