Distribution of Streptococcus mutans and Streptococcus sobrinus in Dental Plaque of Indian Pre-School Children Using PCR and SB-20M Agar Medium
Distribution of Streptococcus mutans and Streptococcus sobrinus in Dental Plaque of Indian Pre-School Children Using PCR and SB-20M Agar Medium
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DOI：
10.7860/jcdr/2016/19256.8909
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发表时间：
2016-11-01
影响因子：
0.2
通讯作者：
Chopra, Radhika
中科院分区：
文献类型：
--
作者：
Singla, Divya;Sharma, Arun;Chopra, Radhika
前言：龋齿是影响口腔的最常见的传染病之一。在口腔细菌中，变形链球菌被认为是主要的致龋细菌，因为它们可以产生高水平的致龋物质，如乳酸和胞外多糖。本研究旨在应用聚合酶链反应（PCR）方法检测牙菌斑中变形链球菌和远缘链球菌的存在，使用改良的蔗糖-杆菌肽（SB-20 M）琼脂培养基定量这些微生物，并将它们在活跃龋（CA）和无龋（CF）学龄前儿童中的存在相关联。68名3-5岁学龄前儿童被平均分为34名CA和34名CF儿童。牙菌斑样本通过PCR方法检测这些微生物，并使用SB-20 M培养基进行定量。采用SPSS 16统计软件对数据进行分析。对于统计分析，使用菌落形成单位（CFU）的频率和平均值，CI = 95%。对于双变量分析，在5%显著性水平下使用Fisher精确检验。两种方法的菌落数均值比较。和S.用Mann Whitney U检验和斯皮尔曼Rho检验在1%的显著性水平上对CA组dmft与CFU进行相关性分析。CA组sobrinus显著高于CF组，S.变异株之间无显著性差异。对这些微生物的定量，S。与CF组相比，CA组中存在显著更高数量的sobrinus。将菌落数/ml与dmft指数进行相关分析，两者呈正相关。和S.与CF儿童相比，CA儿童中检测到更多的sobrinus。PCR是一种敏感、特异、快速、有效的口腔微生物检测方法。
Introduction: Dental caries is one of the most common infectious diseases affecting the oral cavity. Among the oral bacteria, mutans streptococci have been implicated as major cariogenic bacteria as they can produce high levels of dental caries causing substances such as lactic acid and extracellular polysaccharides.Aim: The aim of the study was to detect the presence of Streptococcus mutans and Streptococcus sobrinus in dental plaque by using Polymerase Chain Reaction (PCR) method, quantification of these micro-organisms using Modified Sucrose-Bacitracin (SB-20M) agar medium and to correlate their presence in Caries Active (CA) and Caries Free (CF) preschool children.Materials and Methods: Sixty-eight pre-school children, in the age group of 3-5 years were divided equally into 34 CA and 34 CF children. Dental plaque samples were obtained for detection of these microorganisms by PCR method and quantification was done using SB-20M culture medium. The data was analyzed using statistical software SPSS version 16. For statistical analysis, the frequencies and means of Colony Forming Units (CFU) were used with CI = 95%. For bivariate analysis, Fisher exact test was used at 5% level of significance. The comparison of mean of number of CFU of S. mutans and S. sobrinus was made by Mann Whitney U test and Spearman's Rho test at 1% level of significance was used for correlation between dmft and CFU in CA group.Results: The results showed that S. sobrinus was significantly higher in CA group as compared to CF group whereas S. mutans showed no significant difference. On quantification of these micro-organisms, S. sobrinus was present in significantly higher numbers in CA group as compared to CF group. On correlating the CFU/ml of the micro-organisms with the dmft index, both the micro-organisms showed a positive correlation.Conclusion: We conclude that S. mutans and S. sobrinus were detected in higher numbers in CA children as compared to CF children. PCR is a sensitive, specific, rapid and an effective method for the detection of oral microorganisms.