灰色链霉菌RX-17溶菌酶防治龋病的实验研究

目的:研究灰色链霉菌RX-17溶菌酶在动物口腔内对致龋菌变形链球菌的溶解作用及对龋病发生、发展的抑制作用,为将该溶菌酶用于人类龋病防治提供依据。方法:给大鼠口腔接种变形链球菌,并饲以致龋饲料2000#,分别喂以蒸馏水、氟化钠水溶液、RX-17溶菌酶液,测定牙菌斑pH值,菌斑取样、细菌培养计数,取上下颌骨进行Keyes龋齿计分。结果:RX-17溶菌酶组大鼠牙菌斑pH值高于蒸馏水组(P<0.05),低于氟化钠组(P<0.05)。变形链球菌计数在RX-17溶菌酶组少于蒸馏水组(P<0.01)和氟化钠组(P<0.05)。Keyes计分结果显示,RX-17溶菌酶组E级龋损和Ds级龋损均低于蒸馏水组(P<0.01),但与氟化钠组无差异(P>0.05)。结论:RX-17溶菌酶可以抑制大鼠口腔内变形链球菌的生长和龋病的发生、发展,其防龋效果与氟化钠相当,有可能成为一种新的防龋药物。

Inhibitory effect of a bacteriolytic enzyme derived from streptomyces griseus RX-17 on cariogenicity in rats

Objective: To investigate the effect of RX-17 bacteriolytic enzyme derived from streptomyces griseus on the growth of a cariogenic microbe streptococcus mutans and the development of caries in rats. Methods: Wistar rats were fed with cariogenic forage 2000# and orally infected with streptococcus mutans. The rats were divided into 3 groups and administered with distilled water,sodium fluoride and RX-17 bacteriolytic enzyme, respectively, then the plague pH, germiculted plague bacteria, and obtained jaws were measured for evaluating caries scores by Keyes method. Results: Plague pH of RX-17 bacteriolytic enzyme group was significantly higher than that of distilled water group(P<0.05),but lower than that of sodium fluoride group(P<0.05). The number of streptococcus mutans was significantly less in RX-17 bacteriolytic enzyme group than in both distilled water group and sodium fluoride group (P<0.01 and P<0.05). According to Keyes scores, the number of RX-17 bacteriolytic enzyme group at E and DS levels was significantly less than that of distilled water group (P<0.01), but had no significant difference with that of the sodium fluoride group(P>0.05). Conclusions: RX-17 bacteriolytic enzyme can inhibit the growth of streptococcus mutans and the development of caries, as the sodium fluoride does. RX-17 bacteriolytic enzyme may be used as a novel anti-caries agent.