Liu Jiarong, Bian Zhuan, Fan Mingwen, He Hong, Nie Min, Fan Bing, Peng Bin, Chen Zhi
Key Laboratory for Oral Biomedical Engineering, Ministry of Education, School and Hospital of Stomatology, Wuhan University, Wuhan, PR China.
Caries Res. 2004 Nov-Dec;38(6):523-9. doi: 10.1159/000080581.
The aim of this study was to clarify the genotypic stability of mutans streptococci (MS) longitudinally during orthodontic treatment. Plaque samples were obtained from the supragingival smooth surface of the upper right teeth at four stages: prior to and after 1, 3 and 6 months of orthodontic treatment. Levels of total viable count, total streptococci and MS in dental plaque of 17 patients were recorded. Streptococci isolated from dental plaque samples were identified as MS on the basis of their morphological and biochemical properties. DNA was prepared from 713 strains of MS and the strains were then identified with polymerase chain reaction (PCR) again. Arbitrarily primed PCR (AP-PCR) fingerprinting was applied in determining the genotypes of MS. The results indicated that levels of total viable count, total streptococci and MS increased significantly after the fixed appliances were bonded. A maximum of 3 different genotypes were found in an individual. All the genotypes were found again after the application of the fixed appliances in 17 patients. A new AP-PCR typing pattern was found after the application of fixed appliances for 1 month in patient 1. That strain was not detected either prior to or after 3, or 6 months of treatment. The result indicated that the MS clones were very stable during orthodontic treatment.
本研究的目的是纵向阐明正畸治疗过程中变形链球菌（MS）的基因型稳定性。在四个阶段从右上牙的龈上光滑表面获取菌斑样本：正畸治疗前、治疗1个月后、3个月后和6个月后。记录了17例患者牙菌斑中的总活菌数、总链球菌数和MS水平。根据菌斑样本中分离出的链球菌的形态和生化特性将其鉴定为MS。从713株MS中提取DNA，然后再次用聚合酶链反应（PCR）对菌株进行鉴定。应用任意引物PCR（AP-PCR）指纹图谱法确定MS的基因型。结果表明，固定矫治器粘结后，总活菌数、总链球菌数和MS水平显著增加。个体中最多发现3种不同的基因型。在17例患者应用固定矫治器后，所有基因型均再次出现。患者1在应用固定矫治器1个月后发现了一种新的AP-PCR分型模式。在治疗3个月或6个月之前或之后均未检测到该菌株。结果表明，MS克隆在正畸治疗过程中非常稳定。
