选用大肠杆菌k-12及其耐利福定菌株,利用同位素示踪技术研究发现利福定明显抑制~3H-尿苷掺入敏感菌,而耐药菌掺入则不受抑制,加用膜通透剂EDTA后,~3H-尿苷掺入耐药菌受到明显的抑制;~3H-利福定透入耐药菌的量明显低于透入敏感菌的量,用EDTA后,透入耐药菌中的~3H-利福定显著增加。结果提示:细菌包膜屏障通透性降低使药物进入菌体减少是细菌对利福定耐药的重要机制之一。 The use of E. coli k-12 and its rifampicin strains, the use of isotope tracing technology found that rifampin significantly inhibited the incorporation of 3H-uridine into susceptible bacteria, while the incorporation of resistant bacteria is not inhibited, with the membrane After penetrating EDTA, ~ 3H-uridine incorporation of resistant bacteria was significantly inhibited; the amount of ~ 3H-rifamycin permeable resistant bacteria was significantly lower than the amount of permeable susceptible bacteria, with EDTA, the penetration ~ 3H-rifabutin resistant bacteria significantly increased. The results suggest that the decrease of permeability of bacterial envelope barrier makes the drug enter into the cell body reduce is one of the important mechanisms of bacterial resistance to rifabutin.