Acevedo Ana M, Ray Maria V, Socorro Mairobys, Rojas-Sánchez Fátima
Institute of Dental Research, School of Dentistry, Central University of Venezuela, Caracas, Venezuela.
Acta Odontol Latinoam. 2009;22(1):15-20.
Mutans Streptococci, in particular S. mutans and S. sobrinus, are generally considered to be the prime etiological bacteria of human dental caries. The aim of this study was to determine the frequency of mutans streptococci in dental plaque in three groups of caries-free and caries-affected Venezuelan children aged 2-6, 7-12, 13-19 years, and their possible association with dental caries. The frequency of mutans streptococci was determined in samples of pooled dental plaque collected from all detectable sources of 30 (62.5%) caries-affected and 18 (37.5%) caries-free children. The samples were collected from all available tooth sites using a Hollenbak probe and immediately suspended in Ringer's solution, serially diluted and cultured in Mitis Salivarius (MS) agar for total streptococci determination and Mitis Salivarius Bacitracin (MSB) for isolation of mutans streptococci. The bacterial identification procedure was done using the API Rapid Strep System. The criteria used to determine dmft and DMFT was established by Klein and Palmer (1941). Mean dmft and DMFT were 6.4 +/- 3.2 and 4.4 +/- 2.9, respectively. Ten (33%) out of 30 caries-affected children harbored mutans streptococci. The species most frequently found were S. mutans (20%), S. sobrinus (10%) and S. rattus (3.3%). Meanwhile, in the caries-free group only 6 out of 18 children (33%) harbored mutans streptococci, specifically S. mutans and S. sobrinus, both at 17%, with no significant difference between the two groups. These results indicate that the percentage of children that harbored mutans streptococci was similar in both groups, suggesting that other acidogenic species may be responsible for caries development.
变形链球菌，尤其是变形链球菌和远缘链球菌，通常被认为是人类龋齿的主要致病菌。本研究的目的是确定三组年龄在2 - 6岁、7 - 12岁、13 - 19岁的无龋和患龋委内瑞拉儿童牙菌斑中变形链球菌的频率，以及它们与龋齿的可能关联。从30名（62.5%）患龋儿童和18名（37.5%）无龋儿童所有可检测部位采集的混合牙菌斑样本中，测定变形链球菌的频率。使用Hollenbak探针从所有可用牙齿部位采集样本，并立即悬浮于林格氏溶液中，进行系列稀释，然后在唾液链球菌培养基（MS）琼脂中培养以测定总链球菌，在含杆菌肽的唾液链球菌培养基（MSB）中培养以分离变形链球菌。使用API快速链球菌系统进行细菌鉴定。用于确定dmft和DMFT的标准由Klein和Palmer（1941年）制定。平均dmft和DMFT分别为6.4±3.2和4.4±2.9。30名患龋儿童中有10名（33%）携带变形链球菌。最常发现的菌种是变形链球菌（20%）、远缘链球菌（10%）和鼠链球菌（3.3%）。同时，在无龋组中，18名儿童中只有6名（33%）携带变形链球菌，具体为变形链球菌和远缘链球菌，均为17%，两组之间无显著差异。这些结果表明，两组中携带变形链球菌的儿童百分比相似，这表明其他产酸菌种可能是龋齿发展的原因。
