【摘要】 目的:探讨变形链球菌葡糖基转移酶(GTF)基因B-1923位点多态性与龋易感性的关系。方法:分别从高龋患者(94株)及无龋人群(59株)后牙特定部位可培养的龈上菌斑中培养、分离并鉴定出变形链球菌血清C型临床分离株153株,提取全菌DNA,经PCR扩增gtfB后,采用限制性内切酶EcoRⅠ进行限制性片段长度多态性(RFLP)分析。以GS5作为国际参考株。结果:高龋组和无龋组变形链球菌临床分离株经EcoRⅠ酶切后RFLP酶谱中出现了A型(EcoRⅠ位点存在,与国际参考株GS5一致)和B型(EcoRⅠ位点消失)2种基因型。A型菌株在高龋人群中检出的比例为67%(63/94),高于无龋人群的36%(21/59);而B型菌株在无龋人群中检出的比例为64%(38/59),高于高龋人群的33%(31/94)(χ2=14.460,P<0.001)。携带A型基因的人群高龋患病的风险增加,OR及95%CI为3.677(1.854～7.293)。结论:变形链球菌(血清C型)临床分离株gtfB-1923位点多态现象与龋易感性可能有一定关系。更多还原

【Abstract】 Aim:To find the relationship between genetic diversity in glucosyltransferase B-1923 site of streptococcus mutans and dental caries susceptibility.Methods:The experimental groups comprised caries-free(n = 59) and caries-active(n =94) groups.Plaque was removed from the special parts of enamel surface.The samples were cultured,separated and identified.A total of 153 streptococcus mutans species were isolated for incubation and then purified.The gtfB of the DNA from isolates was amplified by PCR.Genetic diversity of gtfB-1923 site was accessed using restriction fragment-length polymorphism(RFLP) with restriction endonucleases EcoRⅠ.Results:After using the restriction endonuclease EcoRⅠ to make RFLP analysis for the amplified products,there emergerd two genotypes in RFLP map:type A(present at site EcoRⅠ) identical to the international reference strain GS5 as well as type B(not present at site EcoRⅠ).The detection rate of genotype A strains in caries-active group[67%(63 /94) ]was much higher than that in caries-free group[36%(21 /59) ]and the detection rate of genotype B strains in caries-free group[64%(38 /59) ]was much higher than that in cariesactive group[33%(31 /94) ](χ2 = 14.460,P < 0.001).The risk of caries of the group with genotype A increased(OR = 3.677,95% CI 1.854 ～ 7.293).Conclusion:The genetic diversity in glucosyltransferase B-1923 site of streptococcus mutans(type C) isolated strains might relate to dental caries susceptibility.更多还原