Department of Periodontology, Collegeof Dentistry, University of Florida, Gainesville, FL 32610, USA.
Oral Dis. 2010 Oct;16(7):686-95. doi: 10.1111/j.1601-0825.2010.01678.x.
This study was designed to test the hypothesis that periodontal pathogens Tannerella forsythia and Porphyromonas gingivalis are synergistic in terms of virulence potential using a model of mixed-microbial infection in rats.
Three groups of rats were infected orally with either T. forsythia or P. gingivalis in mono-bacterial infections or as mixed-microbial infections for 12 weeks and a sham-infected group were used as a control. This study examined bacterial infection, inflammation, immunity, and alveolar bone loss changes with disease progression.
Tannerella forsythia and P. gingivalis genomic DNA was detected in microbial samples from infected rats by PCR indicating their colonization in the rat oral cavity. Primary infection induced significantly high IgG, IgG2b, IgG1, and IgG2a antibody levels indicating activation of mixed Th1 and Th2 immune responses. Rats infected with the mixed-microbial consortium exhibited significantly increased palatal horizontal and interproximal alveolar bone loss. Histological examinations indicated significant hyperplasia of the gingival epithelium with moderate inflammatory infiltration and apical migration of junctional epithelium. The results observed differ compared to uninfected controls.
Our results indicated that T. forsythia and P. gingivalis exhibit virulence, but not virulence synergy, resulting in the immuno-inflammatory responses and lack of humoral immune protection during periodontitis in rats.
本研究旨在通过大鼠混合微生物感染模型，检验牙周病原菌福赛拟杆菌和牙龈卟啉单胞菌在毒力潜能方面具有协同作用的假设。
三组大鼠分别经口感染单细菌感染或混合微生物感染 12 周，假感染组作为对照。本研究观察了细菌感染、炎症、免疫和牙槽骨丢失随疾病进展的变化。
PCR 检测到感染大鼠微生物样本中存在福赛拟杆菌和牙龈卟啉单胞菌的基因组 DNA，表明它们在大鼠口腔中的定植。初次感染诱导了显著高水平的 IgG、IgG2b、IgG1 和 IgG2a 抗体，表明混合 Th1 和 Th2 免疫应答被激活。混合微生物联合体感染的大鼠表现出腭水平和近中牙槽骨丢失显著增加。组织学检查显示牙龈上皮明显增生，伴有中度炎症浸润和结合上皮的根尖迁移。与未感染对照组相比，观察到的结果存在差异。
我们的结果表明，福赛拟杆菌和牙龈卟啉单胞菌具有毒力，但没有协同毒力，导致大鼠牙周炎中免疫炎症反应和缺乏体液免疫保护。
