龈内阿米巴的致病作用人群调查及动物实验研究

目的 研究齿龈内阿米巴（Entamoeba gingivalis,Eg）致病作用及其与牙周病的关系.方法 给大鼠免疫抑制剂（醋酸泼尼松龙）,用细钢丝结扎下颌切牙的颈部,在Eg组和对照组大鼠分别用齿龈内阿米巴和生理盐水涂抹龈缘,观察大鼠发病和病理改变情况,调查人群感染齿龈内阿米巴情况.结果 Eg组大鼠牙周组织发病率高于对照组（P＜0.01）,Eg组大鼠牙龈上皮组织溃疡、炎症细胞浸润、牙龈沟内上皮增生、牙周脓肿形成、牙槽骨吸收和脓液查见活齿龈内阿米巴,对照组未见病理改变;牙周病患者感染率高于健康人群（P＜0.01）.结论 齿龈内阿米巴是一种机会致病原虫,当宿主免疫力下降时,可致牙周病.

Investigation of human and rat model with infection of Entamoeba gingivalis

Objective To explore the pathogenesis of Entamoeba gingivalis and its correlation to periodontal diseases.Mdthods After treatment with immuno-suppressive drugs,the necks of mandibular incisor of the rats were ligated with a thin steel wire.The gingival margin was smeared with E gingivalis or saline.Incidence and pathological changes were observed.The pathogenicity and infective rate of E gingivalis was investigated.Results The incidence of periodontal diseases in rats infected by E gingivalis was higher than that of control group(P<0.01).The rat gingival epithelial tissue was ulcerated,inflamed cells were infiltrated,epithelium in gingival channel proliferated,periodontal abscess formed,and alveolar bone was found.Living E gingivalis was found in the abscess liquid.There was no pathological change in control group.The infective rate of E gingivalis was higher in patients with periondontal diseases than in healthy groups.Conclusion E gingivalis is an opportunistic pathogen and can cause periodontal diseases in hosts with low immunity.