细胞质外功能σ因子在牙龈卟啉单胞菌生物膜形成中的作用

摘要

Objective To investigate the role of extracytoplasmic function(ECF)sigma factor in the biofilm formation of Porphyromonas gingivalis .Methods The turbidity of Porphyromonas gingivalis cultures was adjusted to absorbance at 600 nm(A 600 )of 0.1 and seeded into 12-well plates. After anaerobic incubation for two days,the medium was removed and 0.5 ml of 0.1% crystal violet solution was added.After dissolving the crystal violet retained in the biofilm,A 600 was measured.The strain of ECF sigma factor suspected to be associated with biofilm formation was cultured repeatedly with the procedure mentioned above.Results The growth of all five Porphyromonas gingivalis strains disrupted the ECF sigma factor gene was slower than that of the common strains in the exponential phase(P <0.05),of which the growth of PGN_1740 mutant was the slowest.The relative biofilm qualities of PGN _ 0274 and PGN _ 1740 mutants were higher than those of common strains (P <0.05).Conclusion The ECF sigma factor of Porphyromonas gingivalis is involved in biofilm formation,in which PGN_0274 and PGN_1740 play a key role.%目的 研究细胞质外功能 σ因子在牙龈卟啉单胞菌生物膜形成中的作用.方法 将牙龈卟啉单胞菌培养物的浊度[600 nm处吸光度(A 600)值]调节至0.1,接种并厌氧培养2 d后,取培养基加入0.1%结晶紫溶液0.5 ml,溶解保留在生物膜中的结晶紫后测量A 600值.对怀疑与生物膜形成相关的细胞质外功能σ因子的菌株,再次培养后重复前述实验过程.结果 所有5种破坏细胞质外功能σ因子基因的牙龈卟啉单胞菌在指数期的生长比普通菌株更慢(P<0.05);其中,PGN_1740突变体生长最为缓慢.PGN_0274和PGN_1740突变体的生物膜相对质量高于普通菌株(P<0.05).结论 牙龈卟啉单胞菌细胞质外功能σ因子参与生物膜形成;其中,PGN_0274和PGN_1740在生物膜形成中发挥关键作用.