DL473是一种新的半合成利福霉素。本文报道了DL473对一些革兰氏阳性、革兰氏阴性及分枝结核杆菌的体内外抗菌活性。在体外活性研究中,DL473对一些临床分离的分枝结核杆菌的活性比利福平大2～10倍,对实验室和临床分离的革兰氏阳性、革兰氏阴性菌的作用比利福平差。培养基内血清浓度对DL473的最小抑菌浓度MIC影响 DL473 is a new semi-synthetic rifamycin. This article reports the antibacterial activity of DL473 against some Gram-positive, Gram-negative and Mycobacterium tuberculosis in vitro and in vivo. In in vitro activity studies, DL473 is 2- to 10-fold more active against some clinically isolated Mycobacterium tuberculosis than rifampicin and is more potent against laboratory-and clinical-isolated Gram-positive, Gram-negative bacteria Adjustment. The effect of serum concentration in culture medium on the minimum inhibitory concentration (MIC) of DL473