利福定耐药机制探讨——耐药菌及敏感菌的形态学比较

STUDIES ON RESISTANT MECHANISM OF BACTERIA TO A NEW ANTITUBERCULOSIS AGENT RIFANDIN(R-761)——MORPHOLOGICAL AND ULTRASTRUCTURE COMPARIS-ION OF SENSITIVE AND RESISTANT CELLS

本文报道利福定耐药及敏感细菌的形态学比较。扫描电镜见大肠杆菌耐药菌菌体变短,表面较敏感菌坚实、粗糙;透射电镜观察见耐药菌外膜增厚,电子密度增加。敏感菌以利福定(100μg/ml)处理4h后,光镜下可见菌体变得模糊,出现溶解现象;透射电镜见胞质疏松、核糖体减少并出现空泡。耐药菌经药物处理后无明显改变,但用药时加用EDTA,则出现与敏感菌类似的改变。该结果支持利福定耐药性与细菌包膜屏障改变有关。

Morphological changes were observed by electron microscope. Ultrastructure comparision of sensitive and resistant cells showed that the surface of the resistant cells was coarser and harder, the outermembrane became thicker and increased electron density. The sensitive cells treated with R761 (100μg/ml) for hours, marked changes were observed in their compact structure. The ribosomes became irregular and vacuoles appeared in the cytoplasm. Resistant cells were found the same changes when treated with R761 and EDTA. If only use R761, no pronounced changes were noted. These results supported the conclusion that the resistant mechanism of bacteria to R761 referred to a decrease in the permeability of envelope barrier to the drug, which may play an important role.