Study of susceptibility genes for oral infectious diseases relating to biofilm in elderly

口腔是病原微生物预定植和感染的储存库。老年人往往难以照顾自己，导致口腔健康状况不佳，牙齿表面严重形成含有机会致病菌的牙生物膜。白色念珠菌、肠杆菌科、假单胞菌、葡萄球菌、嗜麦芽克雷伯菌、肺炎克雷伯菌、粘质克雷伯菌、CNS和产氧克雷伯菌常被分离。本研究的目的是确定与生物膜相关的口腔感染性疾病的易感基因。E2f1缺陷（E2f1-/-）小鼠表现为唾液分泌减少和口腔细菌定植上调。此外，唾液中淀粉酶、粘蛋白和sIgA的产生也增加了。控制这些蛋白的基因也是除E2F-1基因外的易感基因之一。高抗体组（3<a）唾液中变形链球菌数量低于无抗体组（0.1>a）和中等抗体组（3≧a> a）。DRB1^*1502和DRB1^*0406等位基因被显著纠正，抗体高诱导，也倾向于减少乳酸杆菌和变形链球菌。此外，在口服注射抗SDF-1抗体的NOD小鼠中，变形链球菌在接种90 min和120 min后在牙表面定植。综上所述，E2F-1、淀粉酶、粘蛋白、sIgA、DRB1和SDF-1可能是与生物膜相关的口腔感染性疾病的候选易感基因。在未来的工作中，我们将在模型小鼠研究和人类DNA样本的体外研究中证实这些基因是否为易感基因。我们的研究结果为口腔生物膜形成或感染的研究提供了有效的易感基因，并可能有助于确定机会窗口，为预防和预测口腔疾病提供信息

The oral cavity is a reservoir for pre-colonization and infection by pathogenic microorganisms. Elderly people often have difficultly caring for not themselves, and as a result show in poor oral health conditions and severe formation of dental biofilm containing opportunistic pathogens on tooth surfaces. C albicans, Enterobacteriaceae, Pseudomonas sp., S. areus, X. maltophilia, K. pneumoniae, S. marcescens, CNS, and K. oxytoca were frequently isolated. The aims of this study is to identify susceptibility genes for oral infectious diseases relating to biofilm. E2f1 deficient (E2f1-/-) mice presented the dreasing production of saliva and upregulating colonization of oral bacteria. Moreover, production of amylase, mucin and sIgA rose in saliva. The genes controling these proteins also are one of susceptibility genes in addition to E2F-1 gene. Number of mutans streptococi in saliva were lower in high antibody group (3<a) than no antibody (0.1>a) and moderate group (3≧a>1). Allle DRB1^*1502 and DRB1^*0406 were significantly corrected with high induction of the antibodies and also tended to reduce Lactobacilli and S. mutans. Moreover, S. mutans colonized on the tooth surfaces at 90 min and 120 min after the oral inoculation in NOD mice injected with anti- SDF-1 antibodies. Together, it was possible that E2F-1, amylase, mucin, sIgA, DRB1 and SDF-1 were candidate of susceptibility genes for oral infectious diseases relating to biofilm.In the future work, we confirme whether the present genes are the susceptibility genes in model mouse study, and in vitro study using human DNA samples. Our findings demonstrate the effective susceptibility genes for the study of oral biofilm formation or infection, and may help to define the window of opportunity and provide informations for prevention and prediction to dental diseases