中文摘要：

目的调查不同fimA基因型牙龈卟啉单胞菌（P．gingivalis）在牙周健康人群中的分布情况。方法收集136例牙周健康者的龈下菌斑样本，采用16S rRNA PCR法检测P．gingivalis；并根据各fimA基因型特异性引物，用PCR法检测不同fimA基因型P．gingivalis的分布。结果136例牙周健康者的龈下菌斑样本中携带P．gingivalis的阳性率为22．1％。大多数受检者龈下菌斑中只检测到1种fimA基因型P．gingivalis菌株（80．0％）；5例样本检出了2种fimA型P．gingivalis（16．7％），且均为ⅠfimA型与其它fimA型P．gingivalis的联合检出。各fimA型P．gingivalis的检出情况：Ⅰ型（66．7％）、Ⅰb型（6．7％）、Ⅱ型（6．7％）、Ⅲ型（10％）、Ⅳ型（6．7％）、Ⅴ型（16．7％）。Ⅰ型的检出率明显高于其它各型，差异有统计学意义（P〈0．05）；其它各fimA型P．gingivalis间的检出差异均无统计学意义。结论本研究条件下ⅠfimA型P．gingivalis在牙周健康人群中检出例数最高，提示：我国牙周状况不同人群携带的P．gingivalis菌株fimA基因型可能存在差异。

英文摘要：

Objective To investigate the distribution of fimA genotype of P. gingivalis in periodontally healthy adults. Methods Subgingival plaque samples were collected from 136 periodontally healthy adults. P. gingivalis was detected by P. gingivalis PCR. fimA type-specific primers were designed and the distribution of fimA genotypes of P. gingivalis in periodontally healthy adults was detected by PCR. Results P. gingivalis was detected in 22.1% of the healthy subjects. Among the P. gingivalis-positive healthy adults, the most prevalent fimA genotype of P. gingivalis was type Ⅰ. Significant differences （ P 〈 0.05） were found between fimA genotype Ⅰ and other fimA genotypes. A single fimA genotype was detected in most subgingival plaque samples （80.0%）. The distribution of 6 fimA genotypes among P. gingivalis-positive healthy adults was as follows： type Ⅰ （66.7%）; type Ⅰb（6.7%）;type Ⅱ （6.7%）; type Ⅲ（10.0%）; type Ⅳ（6.7%）; type Ⅴ（16.7%）. Conclusion fimA genotype Ⅰ of P. gingivalis was more predominant in periodontally healthy adults, and it may be associated with the healthy periodontal status.