牙周致病菌密度感应信号系统luxS基因的检测

Detection of luxS gene of quorum sensing signal system in periodontal pathogen

目的检测牙周可疑致病菌密度感应信号系统luxS基因，了解其在牙周致病菌中的分布。方法选取牙龈卟啉单胞菌、伴放线放线杆菌、具核梭杆菌的模式株、参考株及临床分离株作为研究对象，提取DNA，通过聚合酶链反应（PCR）、电泳鉴定和DNA测序，并利用GenBank数据库的Blast检测以上细菌luxS基因的存在情况。结果电泳鉴定存在目的条带，测序和Blast检测表明牙龈卟啉单胞菌PCR产物与目的基因有高度一致性（均为99％以上），具核梭杆菌测序结果与GenBank数据库的基因相同，伴放线放线杆菌电泳鉴定结果显示存在目的条带（750bp），与参考条带大小一致。结论本实验引物设计合理，能较好地扩增出牙龈卟啉单胞菌、具核梭杆菌、伴放线放线杆菌各实验菌株的luxS基因，为进一步研究luxS基因的功能奠定了基础。

Objective To detect the presence and distribution of luxS gene in quorum sensing signal system in the periodontal pathogens. Methods The total DNA of Porphyromonas gingivalis （ Pg）, Fusobacterium nucleatum （Fn）, Actinobacillus acitinomycetimcomtans （Aa） were extracted. The presence of luxS was detected by polymerase chain reaction （PCR）. The products of PCR were detected by electrophoresis, sequenced and identified by a Blast search of the GenBank database. Results Electrophoresis, sequencing and Blast searching indicated that the PCR products of Pg were highly consistent with the luxS gene in GenBank. The sequencing result of Fn was also identified with the target gene. The PCR product of Aa was the same as reference through electrophoresis. Conclusions Pg, Fn, Aa contain luxS gene. Further studies may be required to investigate the functions of luxS in the periodontal pathogens.