【摘要】 庆大霉素对E .coli的抑菌作用强 ,试管稀释法、琼脂稀释法和平板抑菌圈法抑菌试验得到一致的MIC(3～5 μg/mL) ;三黄汤、小檗碱抑菌作用弱而稳定 ,试管稀释法测得的MIC分别为 5 0 0mg/mL和 2 .5mg/mL ,而用平板抑菌圈法得不到明显的抑菌圈 .在亚MIC药物液体分批培养时 ,庆大霉素抑菌曲线起初 2h迅速下降 ,而后回升到初始浓度 ,而三黄汤抑菌曲线平缓稳定 ,说明中药和抗生素的抑菌机制明显不同 .庆大霉素与小檗碱混合使用时 ,与庆大霉素单独使用相近 ,而与三黄混合使用时 ,则主要表现三黄汤的抑菌作用 .因此中西药结合时需要慎用 .在接近MIC药物培养基中连续传代 2 0次后 ,庆大霉素MIC提高 8倍多 ,而三黄汤和小檗碱MIC无显著变化 ,无抗药性产生 ,也不产生对庆大霉素的交叉抗药性 .研究结果还表明 ,在 1/ 4MIC三黄汤中连续传代 2 0次 ,能消除E .coli已形成的庆大霉素抗性 ,这为解决抗生素抗药性提供了线索 .图 4参 2 3更多还原

【Abstract】 LB dilution tests, Agar dilution tests, Disk diffusion tests indicated identically that inhibitory activity of gentamicin to E. coli was strong with MIC of 3～5 μg/mL. But Chinese Traditional Medicine sanhuang and berberine exerted weak antibacterial effect by LB dilution tests, in which MIC were 500 mg/mL and 2.5 mg/mL, respectively, and no clear zones of growth inhibition were observed in Disk diffusion tests. In the liquid batch culture for 12 h in the presence of 1 μg/mL gentamicin, the killing curve of E. coli decreased quickly in the first 2 h, and later, increased to the beginning concentration, and when exposed to 250 mg/mL sanhuang or 1 mg/mL berberine, killing curves kept flate on beginning level. When 1/2 MIC gentamicin and 1/2 MIC berberine coexisted, the growth inhibition of E. coli by gentamicin was not affected, otherwise, when 1/2 MIC gentamicin and 1/4 MIC sanhuang was used at the same time, the growth inhibition of E. coli by gentamicin disappeared. Therefore, the mechanisms of growth inhibition to E. coli were obviously different for gentamicin and Chinese Traditional Medicine, and it should be paid much attention to the combinational using of Chinese Traditional Medicine and western medicine. After 20 times serial passage with nigh upon MIC gentamicin and 10% inocula, the MIC of gentamicin to E. coli rose from 4 μg/mL to 25 μg/mL MIC, significant resistance occurred. When 20 times serial passage was performed with 1/4 MIC sanhuang or 1/2 MIC berberine, the MICs of sanhuang, berberine and gentamicin all had no change. What is more valuable is that resistance of E. coli to gentamicin was reversed after 20 times serial passage in 125 mg/mL sanhuang, which provided a approach to solve the problem of antibiotic resistance. Fig 4, Ref 23更多还原