Identification of a new variant of fimA gene of Porphyromonas gingivalis and its distribution in adults and disabled populations with periodontitis
Identification of a new variant of fimA gene of Porphyromonas gingivalis and its distribution in adults and disabled populations with periodontitis
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DOI：
10.1034/j.1600-0765.2002.01637.x
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发表时间：
2002-12-01
影响因子：
3.5
通讯作者：
Hamada, S
中科院分区：
文献类型：
--
作者：
Nakagawa, I;Amano, A;Hamada, S
牙龈卟啉单胞菌菌毛是促进细菌感染的关键。fimA基因编码菌毛的一个亚单位，菌毛蛋白，已被分为五个基因型（类型I至V）的基础上，它们的核苷酸序列。使用fimA类型特异性PCR检测，我们之前的研究证明了具有II型和IV型fimA基因的牙龈卟啉单胞菌与成人牙周炎之间的密切关系。在该研究中，发现一些临床标本对I型和II-fimA特异性引物均呈阳性，这可能是由于样品中两种克隆类型或未知基因型的单一克隆共存。在本研究中，我们从牙龈卟啉单胞菌HG 1691中克隆了一种新的fimA基因变体，命名为Ib型fimA。克隆的fimA基因与I型fimA基因的核苷酸序列同源性为97.1%，表明其为I型fimA的克隆变异体。在13.5%的牙周炎患者和2.9%的牙周健康成人中检测到Ib型fimA微生物。统计分析显示牙周炎与特定fimA类型之间存在密切关系，如Ib型[比值比（OR）6.51]、II型（OR 77.8）和IV型（OR 7.54）。此外，还发现Ib型fimA微生物与唐氏综合征（OR 1.91）和精神残疾人群（OR 4.00）的牙周炎相关。这些发现表明，牙龈卟啉单胞菌与Ib型fimA密切相关的牙周炎的进展，类似于生物体与II型和IV型fimA。
Porphyromonas gingivalis fimbriae are critical for the promotion of bacterial infection. The fimA gene encoding fimbrillin, a subunit of fimbriae, has been classified into five genotypes (types I to V) based on their nucleotide sequences. Using a fimA type-specific PCR assay, our previous study demonstrated a close relationship between P. gingivalis possessing type II and type IV fimA genes and adult periodontitis. In that study, some clinical specimens were found to be positive for both types I- and II-fimA specific primers, likely due to the coexistence of two clonal types or a single clone of an unknown genotype in the samples. In the present study, we cloned a new variant of the fimA gene, designated as type Ib fimA, from P. gingivalis HG1691. The nucleotide sequence of the cloned fimA gene showed a 97.1% homology with that of type I fimA, indicating it as a clonal variant of type I fimA. Organisms with type Ib fimA were detected in 13.5% of periodontitis patients and in 2.9% of periodontal healthy adults. Statistical analysis revealed a strong relationship between periodontitis and specific fimA types such as type Ib [odds ratio (OR) 6.51], type II (OR 77.8), and type IV (OR 7.54). Moreover, type Ib fimA-organisms were also found to be related to periodontitis in Down's syndrome (OR 1.91) and mentally disabled populations (OR 4.00). These findings suggest that P. gingivalis with type Ib fimA is closely associated with the progression of periodontitis, similar to organisms with type II and IV fimA.