Department of Dental pediatrics, Universidad Autónoma de Nuevo León, Mexico.
Eur J Paediatr Dent. 2011 Dec;12(4):220-4.
Streptococcus mutans and Streptococcus sobrinus are the main pathogens associated with the development of dental caries in humans. Recently, the real-time polymerase chain reaction (qPCR-TR) has been used for fast and exact quantification of these bacteria species. This molecular biology method has made the detection of these bacteria in saliva and dental plaque possible; additionally, it aids the development of illness risk prediction. The purpose of this prospective, analytic, transversal, observational and unicenter study was to quantify the spaP gene of the Streptococcus mutans and its correlation with caries in a group of children using isolated DNA from plaque samples processed through qPCR-TR, using specific oligonucleotides for this gene detection.
The cariogenic potential of Streptococcus mutans in the dental plaque was analysed in a group of patients aged 12 to 46 months. A descriptive statistical analysis was performed. The Spearman's correlation coefficient was used to establish the correlation between caries (dmft) index (decayed/missing/filled primary teeth), spaP gene and age group. The Wilcoxon test was used to compare MSB cultivation technique and qPCR-TR.
In the molecular trials, a close association between caries prevalence in childhood and the presence and high proportion of the spaP gene of S. mutans was found. The average caries prevalence was 3.71, and it increased as age range increased. The highest caries prevalence was observed in female patients and in the oldest age range studied (40 46 months) which contrasts with the 12-18 months age that had a caries (dmft) index of zero. The amplification using as initiator the gene spaP of the nucleic acids extracted from the S. mutans resulted positive in 91.3% of the cases. Every child with caries was positive for the spaP and only 8.75% were negative, this group included children without caries.
In conclusion, there was a correlation with infant caries prevalence and S. mutans.
变形链球菌和远缘链球菌是与人类龋齿发展相关的主要病原体。最近，实时聚合酶链反应（qPCR-TR）已被用于快速准确地定量这些细菌种类。这种分子生物学方法使得在唾液和牙菌斑中检测这些细菌成为可能；此外，它有助于疾病风险预测的发展。本前瞻性、分析性、横断面、观察性和单中心研究的目的是使用 qPCR-TR 处理的菌斑样本中的分离 DNA 通过定量 spaP 基因来量化变形链球菌的数量及其与一组儿童龋齿的相关性，使用该基因检测的特定寡核苷酸。
在一组 12 至 46 个月大的患者中分析了牙菌斑中变形链球菌的致龋潜力。进行了描述性统计分析。使用 Spearman 相关系数建立了龋齿（dmft）指数（龋齿/缺失/填充乳牙）、spaP 基因和年龄组之间的相关性。使用 Wilcoxon 检验比较 MSB 培养技术和 qPCR-TR。
在分子试验中，发现儿童龋齿的患病率与 spaP 基因的存在和高比例密切相关。平均龋齿患病率为 3.71，随着年龄范围的增加而增加。女性患者和研究中年龄最大（40-46 个月）的患者龋齿患病率最高，而年龄最小（12-18 个月）的患者龋齿（dmft）指数为零。从变形链球菌提取的核酸中使用 spaP 基因作为起始物进行扩增，91.3%的病例呈阳性。每个患有龋齿的儿童 spaP 均为阳性，只有 8.75%为阴性，该组包括无龋齿的儿童。
总之，婴儿龋齿的患病率与 S. mutans 相关。
