粪肠球菌毒力基因与生物膜形成关系的研究  

Correlation between virulence genes and biofilm formation of Enterococcus faecalis

作　　者：程璐[1] 王肖[1] 招洛丹[1] 彭志翔[1] 

机构地区：[1]中山大学光华口腔医学院.附属口腔医院.口腔医学研究所广东省口腔医学重点实验室,广东广州510055

出　　处：《牙体牙髓牙周病学杂志》2013年第10期627-632,共6页Chinese Journal of Conservative Dentistry

摘　　要：目的:探讨粪肠球菌毒力基因gelE、ebpR、srtA、srtC对粪肠球菌生物膜形成能力及结构的影响。方法:用革兰染色和镜检观察粪肠球菌野生株和gelE突变株、ebpR突变株、srtA突变株、srtC突变株菌落形态及镜下形态;分光光度计检测粪肠球菌野生株OG1RF与各毒力基因突变株细菌的生长状况;将粪肠球菌野生株和各毒力基因突变株接种于BHI培养基,厌氧培养4、8、12、16、20、24、36 h形成生物膜,结晶紫染色后在酶标仪595 nm波长下测其吸光度(OD)值,比较各菌株生物膜的形成量;将粪肠球菌野生株和各毒力基因突变株接种于牙本质片,用BHI厌氧培养16 h时形成生物膜,扫描电镜观察各菌株生物膜的形态和结构。结果:除粪肠球菌毒力基因gelE突变株细胞链长与野生株有差异外,各毒力突变株与野生株形态上无差异,且其生长速度相似;12 h至20 h间,4种突变株生物膜形成量均明显低于野生株(P<0.05);各突变株生物膜形成量以srtA突变株最高,geIE、ebpR突变株次之,srtC突变株最低,差异有统计学意义(P<0.05);扫描电镜观察显示,野生株形成密集、多层融合成片的生物膜结构,而突变株仅可见堆积的微菌落,未形成网络状结构。结论:毒力基因gelE、ebpR、srtA、srtC均能不同程度影响粪肠球菌生物膜的形成量及其空间结构。AIM：To study the correlation between virulence genes gelE,ebpR、srtA,and srtC in Enterococcus faecalis（E.faecalis） and the biofilm formation ability and spatial structure.METHODS：Gram＇s staining was used to observe colony morphology and microscopic morphology of gelE,ebpR,srtA or srtC gene mutants and wild strain of E.faecalis.Spectrophotometer was used to examine the Proliferation of the bacteria.E.faecalis wild-type（WT） strain and its mutant strains were cultured on BHI for 4 h,8 h,12 h,16 h,20 h,24 h and 36 h respectively,the optical density at 595 nm（OD595 nm） was determined using a microplate reader after stained with crystal violet.Scanning electron microscopy （SEM） was used to visualize the structure of biofilm formed on dentine chips by each stains.RESULTS：There was no significant difference in morphology and growth conditions between E.faecalis WT strains and ebpR mutants,srtA mutants or srtC mutants.gelE mutation led to an increase of cell chain length,but the growth curve was similar to that of WT strains.Cultured from 12 h to 20 h,E.faecalis WT strain formed stable mature biofilm.All the four mutant derivatives of E.faecalis showed decreased biofilm formation comparing with WT E.faecalis （P ＜ 0.05）.SEM observation showed that E.faecalis WT strains could adhere to the dentine surface in a dense and confluent pattern while the mutants colonized sparsely.CONCLUSION：Virulence genes gelE,ebpR,srtA,srtC can affect biofilm formation ability and the architecture of E.faecalis biofilm differently.

关 键 词：粪肠球菌 生物膜 毒力基因 扫描电镜 

分 类 号：R780.2[医药卫生—口腔医学]