不同龋敏感性儿童口腔变异链球菌信号分子AI-2活性检测  

Detection of activity of signal molecule AI-2 of streptococcus mutans isolated from children with different caries experience

作　　者：陈岚 韩林秀 吴菊 徐皑 刘兴容 CHEN Lan;HAN Linxiu;WU Ju;XU Ai;LIU Xingrong(Department of Pediatric Dentistry,the Affiliated Stomatology Hospital of Southwest Medical University,Luzhou 646000,China;Department of Stomatology,People's Hospital of Kaizhou District,Kaizhou 405400,China;Oral&Maxillofacial Reconstruction and Re-generation Laboratory,Southwest Medical University,Luzhou 646000,China;Department of Endodontics,the Affiliated Stomatology Hospital of Southwest Medical University,Luzhou 646000,China)

机构地区：[1]西南医科大学附属口腔医院儿童口腔科,泸州646000 [2]重庆市开州区人民医院口腔科,开州405400 [3]西南医科大学口颌面修复重建和再生实验室,泸州646000 [4]西南医科大学附属口腔医院牙体牙髓科,泸州646000

出　　处：《西南医科大学学报》2022年第5期393-398,共6页Journal of Southwest Medical University

基　　金：四川省科技厅-泸州市人民政府-泸州医学院联合科研项目(LY53);四川省卫生厅科研课题(100247);四川省教育厅科研基金(13ZA0235)。

摘　　要：目的探索不同龋敏感性儿童口腔变异链球菌(streptococcus mutans,S.mutans)临床分离株的群体感应信号分子AI-2(autoinducer-2,AI-2)的表达差异。方法以不同龋敏感性儿童口腔分离得到的变异链球菌株(高龋株、中龋株、无龋株)为实验对象,以哈维弧菌BB170(vibrio harveyi BB170)检测各组菌株AI-2的产量,通过实时荧光定量核酸检测系统(real-time quantitative PCR detecting system,RTqPCR)测定高龋株在不同生长时期LuxS与pfs基因的表达量情况,分析AI-2的合成与LuxS、pfs基因的关系。结果各组菌株均能产生AI-2,其中以高龋株产量最多;高龋株在生长的不同时期均有AI-2的表达,在迟缓期、对数前期表达量较少,到对数后期达到峰值(19.00±0.90,P<0.05),为阴性对照的19倍,至稳定期开始下降。RT-qPCR结果显示,高龋株在对数后期LuxS、pfs基因的表达量最高,分别为10.47±0.35、7.22±0.06;LuxS、pfs基因的转录水平与AI-2的产生保持一致,但AI-2的产生与LuxS的相关性更高(P<0.05)。结论致龋敏感性越高的儿童口腔变异链球菌临床分离株产生的信号分子AI-2越多;且AI-2活性与LuxS基因转录水平相关性较pfs基因转录水平相关性高。ObjectiveTo explore the expression differences of the quorum sensing molecule AI-2 of streptococcus mutans isolated from children with different caries experience.MethodsStreptococcus mutans isolated from children with different caries experience(high caries strain,medium caries strain,and non-cariogenic strain)were used as the experimental subjects.Vibrio harveyi BB170 was used to detect the yield of AI-2 in each group.Real-time quantitative PCR detecting system(RT-qPCR)was used to measure the high caries strain’s expression of LuxS and pfs genes at different growth periods,and the relationship between the synthesis of AI-2 and LuxS and pfs genes was analyzed.ResultsAll the strains produced AI-2,the high caries strain had the highest yield.AI-2 expression was found in the high caries strains at different growth stages.The AI-2 of high caries strain had low expression in the lag phase and pre-log phase,and then reached the peak at the post-log phase(19.00±0.90,P<0.05),which was 19 times higher than that of the negative control,and began to decline in the stable phase.RT-qPCR results showed that LuxS and pfs genes of high caries strains had the highest expression in the post-log phase,which were 10.47±0.35 and 7.22±0.06 respectively;The transcriptional level of LuxS and pfs genes were consistent with that of AI-2,but the correlation with LuxS was higher(P<0.05).ConclusionStreptococcus mutans isolated from children with higher caries experience produced more signal molecule AI-2;and the correlation between AI-2 activity and LuxS gene transcription level was higher than that of pfs gene transcription level.

关 键 词：变异链球菌 群体感应 AI-2 LUXS PFS 

分 类 号：R781.1[医药卫生—口腔医学]