Relationship between porphyromonas gingivalis rag locus genotyping and bacterial virulence

GUO Xinghuai; ZHANG Xiaoping; LI Yingxu

doi:10.3969/j.issn.1002-7386.2016.14.010

Abstract：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 R 3 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 R 3 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.