The aim of this study was to determine the prevalence of Streptococcus mutans and its serotypes in samples from oral cavity of young Galician population and their relationship with the oral health state. The variables generally associated with dental caries, such as salivary flow rate, buffering capacity, eating habits, and lifestyle, were also analysed. No relationship was found between the variables studied and the presence of S. mutans in the oral cavity or the existence of dental caries. Presumptive strains of S. mutans were isolated from saliva samples from 48% of the analysed population. The use of conventional microbiological methods, API 20 Strep system, and species-specific polymerase chain reaction (PCR) allowed to substantiate the identity of the strains as S. mutans. Multiplex PCR protocols, developed in this study for the simultaneous detection of S. mutans and serotypes c, e, and f and for detection of S. mutans and serotype k, also confirmed this result and demonstrated that serotype c was predominant in the studied young Galician population (86%). Serotypes e (8%), k (3%), and f (2%) were also detected. Serotype c was detected in carious and caries-free subjects, while the remaining serotypes were only found in subjects with caries.

中文翻译：

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从年轻的加利西亚人口中分离出的变形链球菌菌株的分子和血清学分型：与口腔健康状况的关系。

这项研究的目的是确定年轻的加利西亚人口口腔样本中的变形链球菌的流行及其血清型及其与口腔健康状况的关系。还分析了通常与龋齿有关的变量，例如唾液流速，缓冲能力，饮食习惯和生活方式。在研究的变量和口腔中是否存在变形链球菌或龋齿之间没有发现任何关系。从48％的分析人群的唾液样本中分离出变形链球菌的推定菌株。使用常规的微生物学方法，API 20 Strep系统和物种特异性聚合酶链反应（PCR）可以证实该菌株为变形链球菌的身份。多重PCR方案 在这项研究中开发的用于同时检测变形链球菌和血清型c，e和f以及检测变形链球菌和血清型k的研究也证实了这一结果，并证明了血清型c在研究的加利西亚年轻人中占主导地位（86 ％）。还检测到血清型e（8％），k（3％）和f（2％）。在龋齿和无龋的受试者中检测到血清型c，而其余血清型仅在患有龋齿的受试者中发现。