Distinction of periodontopathogenicity of P. gingivalis based on fimA genotyping

成人牙周炎是一种高度破坏性的慢性炎症性疾病，由一小部分牙周细菌的复杂作用引起。其中，牙龈卟啉单胞菌被认为是一种真正的牙周病原体。这种微生物在牙周炎患者中经常被检测到，而据报道，它在牙周健康人群中出现的频率较低，而没有明显的牙龈炎症。牙周健康的人和牙周炎患者体内的微生物在毒力上可能存在差异。然而，目前尚不清楚牙周炎是否只有在牙龈假单胞菌毒力株(S)存在的情况下才会发生，或者是否其他宿主因素，如遗传背景和环境压力，可能在被该组织感染的个人中对疾病的发生具有决定性影响。编码菌毛亚基fimbrin的牙龈卟啉单胞菌Fima基因已被归类为…根据它们的核苷酸序列进一步分为五种基因类型(类型I到V)。我们调查了这些FIMA基因的流行与成人牙周健康状况之间的关系。在380名牙周健康成人和87名牙周健康成人的牙菌斑标本中检出牙龈假单胞菌的比例为36.8%。在139例牙周炎患者中，有1%的牙周炎患者的牙周病基因中检测到了DNA。在健康人中最常见的FIMA类型是I型(76.1%)，大多数牙周炎患者携带II型FIMA微生物(66。1%)。单变量分析表明，牙周炎与I型FIMA的发生有关(优势比=0。16)、II型(44.44)、III型(1.96)、IV型(13.87)和V型(1.40)。我们进一步比较了I~V型重组FimA(RFimA)对人上皮细胞系(Hep-2细胞)的黏附/侵袭能力。II型rFimA偶联微球对Hep-2细胞的黏附/侵袭作用明显强于其他类型的rFimA。此外，携带FimA基因的HW24D1型牙周炎假单胞菌与细胞的黏附和侵袭能力强于其他FimA基因携带型的菌株，这一结果清楚地表明，牙龈假单胞菌既有与疾病相关的菌株，也有非疾病相关的菌株，如果根据FimA基因的克隆变异来区分致病菌株，对牙周炎的治疗和预后评估都有价值。较少

Adult periodontitis is a highly destructive chronic inflammatory disease resulting from the complex actions of a small subset of periodontal bacteria. Among them, Porphyromonas gingivalis has been characterized as a bona fide periodontal pathogen.This microorganism has been frequently detected in patients with periodontitis, while it reportedly occurs at a lower frequency in periodontally healthy individuals without marked gingival inflammation. There may be diversities in virulence among the organisms harbored by individuals who are periodontally healthy and those with periodontitis. However, it is still unknown whether periodontitis can develop only in the presence of virulent strain(s) of P. gingivalis, or if other host factors, such as genetic background and environmental stress, may have a determining influence in the initiation of the disease in individuals infected by the organism.Porphyromonas gingivalis fimA gene encoding fimbrillin, a subunit of fimbriae, has been classified … More into five genotypes (types I to V) based on their nucleotide sequences. We investigated the relationship between the prevalence of these fimA genotypes and periodontal health status in adults. P. gingivalis was detected in 36.8% of dental plaque specimens from the 380 periodontally healthy adults and in 87. 1% of those from 139 periodontitis patients by PCR method. The most prevalent fimA type was type I (76.1%) in healthy subjects, and a majority of the periodontitis patients carried type II fimA organisms (66. 1 %). The univariate analysis illustrated that periodontitis were associated with the occurrences of type I fimA (odds ratio=0. 16), type II (44.44), type III (1.96), type IV (13.87), and type V (1.40). We further compared adhesion/invasion abilities of recombinant FimA (rFimA) of types I to V to human epithelial cell line (HEp-2 cell). The adhesion/invasion of type II rFimA-conjugated microspheres to HEp-2 cells was significantly greater than those of other rFimA types. Furthermore, P. gingivalis strain HW24D1 with type II fimA adhered to cells and invaded them more than strains with other fimA genotypes.These findings clearly indicate that there are both disease-associated and non-disease-associated strains of P. gingivalis, and it could be of value for their therapeutic aspects and in the assessment of the prognosis of periodontitis if the disease-contributing strains would be differentiated based on the clonal variations of the fimA gene. Less