Danaei Marzieh, Mollaali Milad, Fakharmohialdini Vida, Poureslami Hamidreza, Sajadi Fatemeh Sadat, Gisour Elham Farokh, Jahanimoghadam Fatemeh, Gholampour Aida, Foroudisefat Mehrnaz, Mirshekari Arezoo, Shojaeipour Raziyeh
Dana Gene Pajoohan Karmania Company, Member of Iran High-Tech Laboratory Network, Kerman, Iran.
Department of Biology, Faculty of Science, University of Sistan and Baluchestan, Zahedan, Iran.
Clin Exp Dent Res. 2024 Dec;10(6):e70039. doi: 10.1002/cre2.70039.
Lactobacilli and Streptococcus mutans are stigmatized as cariogenic bacteria, but few studies have simultaneously examined the quantitative and qualitative aspects of lactobacilli and S. mutans in childhood dental caries. Therefore, this study aimed to detect the presence of S. mutans and lactobacilli in dental caries using Snyder's test, colony counting, and PCR in the primary teeth of Iranian children with dental caries.
A cross-sectional study was conducted in Kerman, Iran, from March to Jun 2024. After dental examinations, 120 eligible children aged 5-9 were chosen using simple random sampling and classified into four groups based on their decayed, missing, and filled (primary) teeth (dmft) index: Group 1 (dmft = 0), Group 2 (dmft = 4-6), Group 3 (dmft = 7-9), and Group 4 (dmft = 10-13). The salivary levels of lactobacilli and S. mutans were calculated using colony counting (CFU/ml). Moreover, Snyder's test was applied to evaluate caries activity. PCR was also performed for molecular detection of lactobacilli (16S rRNA gene) and S. mutans (gftB gene). Lastly, the association between bacterial counting, molecular findings, and Snyder's test was estimated through statistical methods using SPSS 27.
Significant differences were found between the age and the PCR results of lactobacilli and S. mutans among all dmft Groups (p < 0.05). Moreover, positive significant correlations were observed between the counts of lactobacilli and S. mutans in dmft Group 1 compared to other dmft Groups (p < 0.05). Furthermore, the counts of these two bacteria differed significantly in Snyder's test (p < 0.05). However, Snyder's test differed significantly from the S. mutans PCR (p < 0.05), but not from the lactobacilli PCR (p > 0.05).
The results of the study could potentially be considered a promising and cost-effective screening program to identify children who are susceptible to dental caries.
乳酸杆菌和变形链球菌被视为致龋菌，但很少有研究同时从定量和定性方面对儿童龋齿中的乳酸杆菌和变形链球菌进行检测。因此，本研究旨在利用斯奈德试验、菌落计数和聚合酶链反应（PCR）检测伊朗患龋儿童乳牙中变形链球菌和乳酸杆菌的存在情况。
2024年3月至6月在伊朗克尔曼进行了一项横断面研究。经过口腔检查后，采用简单随机抽样法选取了120名5 - 9岁符合条件的儿童，并根据其乳牙龋失补牙指数（dmft）分为四组：第1组（dmft = 0）、第2组（dmft = 4 - 6）、第3组（dmft = 7 - 9）和第4组（dmft = 10 - 13）。采用菌落计数法（CFU/ml）计算唾液中乳酸杆菌和变形链球菌的水平。此外，应用斯奈德试验评估龋活性。还进行了PCR以对乳酸杆菌（16S rRNA基因）和变形链球菌（gftB基因）进行分子检测。最后，使用SPSS 27通过统计方法评估细菌计数、分子检测结果与斯奈德试验之间的关联。
在所有dmft组中，乳酸杆菌和变形链球菌的年龄与PCR结果之间存在显著差异（p < 0.05）。此外，与其他dmft组相比，第1组dmft中乳酸杆菌和变形链球菌的计数之间存在显著正相关（p < 0.05）。此外，在斯奈德试验中这两种细菌的计数存在显著差异（p < 0.05）。然而，斯奈德试验与变形链球菌PCR结果存在显著差异（p < 0.05），但与乳酸杆菌PCR结果无显著差异（p > 0.05）。
该研究结果可能被视为一种有前景且具有成本效益的筛查方案，用于识别易患龋齿的儿童。
