Rifampicin is a semi-synthetic broad-spectrum antibacterial drug of the rifamycin class, which has antibacterial activity against a variety of pathogenic microorganisms. The drug has a significant bactericidal effect on Mycobacterium tuberculosis and some non-tuberculous mycobacteria (including Mycobacterium leprae, etc.) both inside and outside the host cells. Rifampicin has a good antibacterial effect on aerobic Gram-positive bacteria, including enzyme-producing strains of Staphylococcus aureus and methicillin-resistant strains, Streptococcus pneumoniae, other Streptococcus, Enterococcus, Listeria, Bacillus anthracis, Clostridium perfringens, Corynebacterium diphtheriae, anaerobic cocci, etc. It also has a high degree of antibacterial activity against aerobic Gram-negative bacteria such as Neisseria meningitidis, Haemophilus influenzae, and Neisseria gonorrhoeae. Rifampicin also has a good effect on Legionella, and has an inhibitory effect on pathogens such as Chlamydia trachomatis, lymphogranuloma venereum, and psittacosis.