【摘要】 目的探讨粪肠球菌心内膜炎抗原EfaA在生物膜形成中的作用。方法微量滴定板法测定生物膜形成能力,将efaA+、efaA-粪肠球菌S14、S14-pAT28、S14-pAT28-efaA分别接种到96孔板,37℃培养24h形成生物膜,结晶紫染色,测定孔板底部生物膜的OD570值;MTT法比较S14、S14-pAT28、S14-pAT28-efaA所形成的生物膜的活菌含量OD492;共聚焦激光扫描显微镜(CLSM)观察比较efaA+、efaA-肠球菌形成的生物膜的平均厚度、最大厚度。结果 efaA+转化株在各培养时间点微量滴定板法测定的生物膜形成能力OD570值、MTT法测定的OD492活菌含量、CLSM观察的生物膜的平均厚度、最大厚度均大于野生株及空质粒转化株,P<0.05;空质粒转化株与野生株比较无显著性差别,P>0.05。结论粪肠球菌心内膜炎抗原efaA基因有利于肠球菌生物膜的形成。更多还原

【Abstract】 In this study,we used E.faecalis(efaA+,efaA-)to study the role of enterococcus endocarditis antigen EfaA on biofilm formation.The ability of biofilm formation were detected by microtiter plate assay.E.faecalis strains S14,S14-pAT28 and S14-pAT28-efaA were cultivated in 96-well for 24hours;biofilms were detected by microtiter plate reader after Gram crystal violet staining.Optical density at 570 nm for each strain were determined and compared.MTT method was used to compare the bioactivity of biofilms of efaA+,efaA-strains by testing the OD492,which indicated the vital bacteria counts of biofilm.The mean thickness and the maximal thickness of biofilms of efaA+,efaA-E.faecalis strains were compared by CLSM.It was shown that the biofilm formation ability(OD570values)of transformant S14-pAT28-efaA detected by microtiter plate assay,the vital bacteria counts(OD492values)of S14-pAT28-efaA tested by MTT method,the mean thickness and the maximal thickness of biofilms of S14-pAT28-efaA observed by CLSM were all greater than that of wild strain(S14)and control strain(S14-pAT28)respectively(P<0.05).There was no significant difference between control strain S14-pAT28 and wild strain S14(P>0.05).It was concluded that E.faecalis EfaA might be in favor of the biofilm formation of E.faecalis.更多还原