Multi-pronged study on actual state and suppression of bacterial biofilm associate with refractory periapical periodontal disease.

我们研究了人根外铃细菌的鉴定和定位。从难治性根尖周炎患者中提取根外生物膜，采用基于pcr的16S rRNA基因检测方法鉴定细菌，并观察选定细菌种类的免疫组织化学定位。常检出核梭菌、牙龈卟啉单胞菌和连生单宁菌。根外生物膜各部位均检出牙龈假单胞菌。核仁单胞菌主要分布在生物膜的中间层，连生单胞菌主要分布在生物膜的表层。另一方面，对根外生物膜中细菌单种生物膜的防治方法进行了研究。采用改良罗宾斯装置制备牙龈假单胞菌381生物膜。盐酸米诺环素和甲硝唑对浮游牙龈假单胞菌有抑制作用，而氯己定和甲硝唑对浮游牙龈假单胞菌无抑制作用。此外，我们发现Er。YAG激光对粪肠球菌、变形链球菌、粘放线菌和痤疮丙酸杆菌的生物膜作用不同。我们分析了与牙龈假单胞菌生物膜形成相关的基因。从牙龈假单胞菌381株中分离到一个糖基转移酶基因，命名为gtfA。gtfa缺乏的牙龈假单胞菌在形态上缺乏成熟的菌毛，自身聚集能力较低，与上皮细胞的附着能力严重受损。提示gtfA可能调节龈下生物膜的附着能力，具有一定的毒力因子作用。研究了根管分离菌在杜仲胶点上的初始生物膜形成能力。粪肠球菌、血链球菌、中间链球菌、化脓性链球菌和金黄色葡萄球菌生物膜在添加45%或90%血清的培养基中培养。粪链球菌和血链球菌的生物膜明显厚于中间链球菌、化脓性链球菌和金黄色链球菌。与具核假单胞菌、痤疮假单胞菌、牙龈假单胞菌和中间普雷沃氏菌孵育的标本未检出生物膜。少

We investigated the identification and localization of the bacteria in human extraradicular bolls. Extraradicular biofilms to identify bacteria using a PCR-based 16S rRNA gene assay, and to observe immunohistochemical localization of selected bacterial species were taken from patients with refractory periapical periodontitis. Fusobacterium nucleatum, Porphyromonas gingivalis, and Tannellera forsythensis were frequently detected. P.gingivalis were detected in all parts of the extraradicular biofilms. F.nucleatum were predominantly scattered at the middle layer, and T.forsythensis located at the superfacial layer in the biofilms.On the other hand, the control methods against single species biofilms of bacteria identified from the extraradicular biofilm were examined. P.gingivalis strain 381 biofilms were prepared using modified Robbins Device. Minocycline hydrochloride and Metronidazole, which showed effect against planktonic P.gingivalis cells, were not effective though chlorhexidine gl … More uconate were effective. Moreover, we found that the effects of Er.YAG laser against Enterococcus faecalis, Streptococcus mutans, Actinomyces viscosus and Propionibacterium acnes biofilms were different.We analyzed the gene associated with biofilm formation of P.gingivalis. A putative glycosyltransferase gene was isolated from P.gingivalis strain 381 and designated as gtfA. GtfA-deficient P.gingivalis lacked mature fimbriae morphologically and showed quite a low ability for autoaggregation, and its ability for attachment to epithelial cells was severely impaired. These results suggested that gtfA might regulate attachment ability in subgingival biofilms and act has a potent virulence factor.The initial biofilm-forming ability of root canal isolates on gutta-percha points was investigated. Enterococcus faecalis, Streptococcus sanguis, Streptococcus intermedius, Streptococcus pyogenes and Staphyrococcus aureus biofilms were generated on the surfaces of the specimens incubated in culture mediums supplemented with 45 or 90 v% serum. E.faecalis and S.sanguis biofilms were significantly thicker than those of S.intermedius, S.pyogenes and S.aureus. No biofilms were detected on the specimens incubated with F.nucleatum, P.acnes, P.gingivalis, and Prevotella intermedia. Less