牙龈卟啉单胞菌rag位点基因分型与细菌致病力的关系研究

Relationship between porphyromonas gingivalis rag locus genotyping and bacterial virulence

目的探讨牙龈卟啉单胞菌rag位点基因分型与细菌致病力的关系。方法选取50例慢性牙周炎患者,每位受试者取3个样本,共150个样本,收集龈下菌斑,通过BHI平板培养病原菌,通过RT-PCR检测rag位点不同基因型的P.gingivalis菌种,根据rag位点不同基因型的P.gingivalis菌种分为R1、R2、R3、R4组和对照组,检测不同基因型P.gingivalis的细菌致病力。结果 150个样本,共计109个样本为P.gingivalis阳性,其中rag-1型检出率明显高于R2~R4组（P〈0.01）,rag-3型次之,与rag-2型、rag-4型比较差异有统计学意义（P〈005）;R1组LPS、LBP、mCD14、MMP-8以及MMP-9显著高于其他各基因型组（P〈0.05或〈0.01）,R3组次之,与R2、R4组比较差异有统计学意义（P〈0.05）;R2组在LPS、LBP、mCD14方面高于R4组（P〈0.05）,而MMP-8、MMP-9两者差异无统计学意义（P〉0.05）。结论 P.gingivalis菌株中rag位点基因分型的细菌致病力：rag-1型最强,次之为rag-3型,较弱的为rag-2型和rag-4型。

Objective To investigate the correlation between porphyromonas gingivalis（ P. gingivalis） rag locus genotyping and bacterial virulence. Methods Fifty patients with chronic periodontitis were enrolled in the study in whom 3 specimens were celleted in every subject,a total of 150 specimens,subgingival plaques were collected,cultured pathogens by means of BHI plates were detected by RT-PCR for identifying P. gingivalis strain in rag locus different genotypes. According to P. gingivalis strain in rag locus different genotypes,which was divided into R1,R2,R3,R4 grpups and control group,then bacterial virulence was detected in the four groups. Results Among 150 specimens,109 specimens were P. gingivalis positive,in which type rag-1 detection rate in R1 group was significantly higher than that in the other three groups（ P 〈0. 01）,next rag-3 type,there was a significant difference between R3 group and R2,R4 groups（ P 〈0. 05）. The levels of LPS,LBP,mCD14,MMP-8 and MMP-9 in R1 group were significantly higher than those in the other 3 groups（ P 〈0. 05 or P 〈0. 01）,next rag-3 type,there were significant differences between R3 group and R2,R4 groups（ P 〈0. 05）. The levels of LPS,LBP,mCD14 in R2 group wee significantly higher than those in R4 group（ P 〈0. 05）,however,there were no significant differences in the levels of MMP-8 and MMP-9 between two groups（ P 〈0. 05）. Conclusion Amiong different P. gingivalis strain rag sites genotypes,the bacteria virulence is the strongest in rag-1 type,followed by a rag-3 type,however,the bacteria virulence is relatively weaker in rag-2 type and rag-4 type.