成人牙周健康状况与fimA基因型牙龈卟啉单胞菌的相关性

目的分析不同fimA基因型牙龈卟啉单胞菌（P.gingivalis）在牙周健康人群和慢性牙周炎人群中的分布，探讨不同fimA基因型P.gingivalis与成人牙周状况的相关关系。方法收集牙周健康组（136例）和慢性牙周炎组（115例）的龈下菌斑样本，采用16S rRNA PCR法检测P.gingivalis，并根据各fimA基因型（Ⅰ～Ⅴ和Ⅰb）的特异性引物检测不同fimA基因型P.gingivalis菌株的分布，计算OR值和95%可信区间。结果牙周健康组和慢性牙周炎组龈下菌斑样本中P.gingivalis阳性率分别为22.1%和81.7%，多数样本中只检测到1种fimA基因型。牙周健康组中ⅠfimA型的检出率最高（占66.7%）；慢性牙周炎组中则为ⅡfimA基因型（占43.6%），其次为Ⅳ和Ⅰb fimA基因型。慢性牙周炎的发生与P.gingivalis的关系密切（OR=16.36），Ⅰ、Ⅰb、Ⅱ、Ⅲ、Ⅳ、ⅤfimA基因型P.gingivalis与慢性牙周炎相关性的OR值分别为0.97、13.26、36.62、4.57、22.86、1.19；ⅡfimA基因型P.gingivalis与慢性牙周炎的相关性最强，其次为Ⅳ和Ⅰb型。结论P.gingivalis菌株的fimA基因型存在差异，特异性fimA基因型P.gingivalis可能与成人慢性牙周炎的发生关系密切。

Prevalence of fimA Genotypes of Porphyromonas gingivalis and Periodontal Health Status

OBJECTIVE: To detect the distribution of fimA genotype of P. gingivalis in periodontally healthy adults and chronic periodontitis patients, and to investigate the relationship between the prevalence of fimA genotype of P. gingivalis and periodontal health status. METHODS: Subgingival plaque samples were collected from 136 periodontally healthy adults and 115 chronic periodontitis patients. The occurrence of P. gingivalis was determined by P. gingivalis 16S rRNA PCR. Distribution of fimA genotype was assessed in P. gingivalis positive samples by PCR using primers pairs homologous to the different fimA genes. RESULTS: P. gingivalis was detected in 22.1% of the healthy subjects and 81.7% of chronic periodontitis patients. A single fimA genotype was detected in most subgingival plaque samples. In P. gingivalis-positive healthy adults, the most prevalent fimA genotype of P. gingivalis was type I fimA. In contrast, a majority of chronic periodontitis patients carried type II fimA, followed by IV fimA and I b fimA. The univariate analysis illustrated that chronic periodontitis was associated with occurrences of type I fimA (OR = 0.97), I b (OR =13.26), II (OR = 36.62), III (OR = 4.57), IV (OR = 22.86), and V (OR = 1.19). CONCLUSION: II fimA genotype of P. gingivalis followed by IV and I b were an important virulence factor that may account for the pathogenesis of chronic periodontitis, suggesting an increased pathogenic potential of these types.