变异链球菌UA159中SMU.2055基因在致龋性的作用

发布时间：2018-03-06 10:03

本文选题：变异链球菌　切入点：乙酰基转移酶　出处：《南方医科大学学报》2017年06期 　论文类型：期刊论文

【摘要】：目的构建变异链球菌(Streptococcus mutans,S.mutans)SMU.2055基因缺陷菌株,确定SMU.2055基因对S.mutans形态及与致龋性相关的生物学特性的影响。方法利用同源重组的方法,构建SMU.2055基因缺陷菌株。在扫描电子显微镜及透射电子显微镜下观察野生菌株及基因缺陷菌株的形态结构。连续监测野生菌株及基因缺陷菌株的菌液A600值及p H值,比较其生长能力及产酸能力。对两种菌株进行酸适应后,分别进行酸冲击,评价其耐酸能力。结果经过聚合酶链反应及测序鉴定,变异链球菌SMU.2055基因缺陷菌株构建成功。扫描电子显微镜结果显示,与野生菌株相比,基因缺陷菌株菌体形态发生改变,菌体间不规则物质较少。透射电子显微镜下观察,基因缺陷菌株细胞膜较模糊,细胞膜完整性被破坏。基因缺陷菌株的生长能力及耐酸能力较野生菌株均有所下降,而基因缺陷菌株与野生菌株间的产酸能力未见明显差异。结论 SMU.2055基因与变异链球菌的形态、生长及耐酸能力密切相关,而对其产酸能力不造成明显影响。
[Abstract]:Objective to construct Streptococcus mutansanus S.mutansa SMU.2055 gene deficient strain and determine the effect of SMU.2055 gene on the morphology of S. mutans and the biological characteristics related to caries. Methods the homologous recombination method was used to determine the effect of SMU.2055 gene on the morphology of S. mutans and the biological characteristics related to caries. SMU.2055 gene deficient strains were constructed. The morphology and structure of wild and gene deficient strains were observed under scanning electron microscope and transmission electron microscope. A600 and pH values of wild and gene deficient strains were continuously monitored. The growth ability and acid production ability of the two strains were compared. After acid adaptation, the two strains were subjected to acid shock to evaluate their acid tolerance. The results were confirmed by polymerase chain reaction (PCR) and sequencing. Streptococcus mutans SMU.2055 gene deficient strain was successfully constructed. The results of scanning electron microscope showed that the morphology of the mutant strain changed compared with that of wild strain, and there were fewer irregular substances between them. The cell membrane of the gene deficient strain was blurred and the integrity of the cell membrane was destroyed. The growth ability and acid tolerance ability of the gene deficient strain were lower than those of the wild strain. Conclusion the SMU.2055 gene is closely related to the morphology, growth and acid-tolerance of Streptococcus mutans, but has no significant effect on the acid-producing ability of Streptococcus mutans.
【作者单位】：南方医科大学南方医院口腔科;南方医科大学口腔医学院;深圳市龙华新区中心医院口腔科;南方医科大学附属广东省口腔医院;
【基金】：南方医科大学南方医院院长基金(2013B003) 深圳市科技计划项目(JCYJ20160428142231354)
【分类号】：R781.1

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