Zhou Yan, Yu Lixia, Tao Ye, Zhi Qinghui, Lin Huancai
Department of Preventive Dentistry, Guanghua School of Stomatology, Sun Yat-Sen University, 56 Ling Yuan Road West, Guangzhou, 510055, China.
Guangdong Provincial Key Laboratory of Stomatology, Sun Yat-Sen University, Guangzhou, 510055, China.
BMC Oral Health. 2017 Jul 14;17(1):114. doi: 10.1186/s12903-017-0407-0.
To explore and analyse the association between biofilm and the genetic polymorphisms of scrA gene of EnzymeIIscr found in clinical isolates of Streptococcus mutans (S. mutans) from severe early childhood caries (S-ECC) in 3 years old children.
Clinical strains of S. mutans were conserved from a previous study. Thirty strains of S. mutans from the S-ECC group and 30 strains of S. mutans from the caries free (CF) group were selected. Biomass and viability of biofilm formed by the strains were evaluated by crystal violet and alamar blue assay. Genomic DNA was extracted from the S. mutans isolates. PCR was conducted to amplify scrA gene. After purified and sequenced the PCR products, BioEdit sofeware was used to analyse the sequence results. A chi-square test was used to compare the results.
Compared to the CF group, the biomass of S-ECC group was higher (P = 0.0424). However, the viability of the two groups showed no significant difference. All 60 clinically isolated S. mutans strains had a 1995 base pair (bp) scrA gene. Forty-nine point mutations were identified in scrA from the 60 clinical isolates. There were 17 missense point mutations at the 10, 65, 103, 284, 289, 925, 1444, 1487, 1494, 1508, 1553, 1576, 1786, 1822, 1863, 1886, and 1925 bp positions. The other 32 mutations were silent point mutations. No positions were found at active sites of ScrA. The statistic analyse showed no significant missense mutation rates between the two groups.
There was no association between biofilm and genetic polymorphisms of scrA from S. mutans with S-ECC in 3 years old children.
探讨并分析变形链球菌临床分离株中生物膜与3岁重度幼儿早期龋（S-ECC）患者中发现的酶IIscr的scrA基因多态性之间的关联。
从先前的研究中保存变形链球菌临床菌株。选取30株来自S-ECC组的变形链球菌菌株和30株来自无龋（CF）组的变形链球菌菌株。通过结晶紫和alamar蓝分析法评估菌株形成生物膜的生物量和活力。从变形链球菌分离株中提取基因组DNA。进行PCR扩增scrA基因。对PCR产物进行纯化和测序后，使用BioEdit软件分析序列结果。采用卡方检验比较结果。
与CF组相比，S-ECC组的生物量更高（P = 0.0424）。然而，两组的活力无显著差异。所有60株临床分离的变形链球菌菌株均有一个1995碱基对（bp）的scrA基因。在60株临床分离株的scrA中鉴定出49个点突变。在第10、65、103、284、289、925、1444、1487、1494、1508、1553、1576、1786、1822、1863、1886和1925 bp位置有17个错义点突变。其他32个突变是沉默点突变。在ScrA的活性位点未发现突变位点。统计分析显示两组之间的错义突变率无显著差异。
3岁S-ECC患儿变形链球菌的生物膜与scrA基因多态性之间无关联。
