Uses: 1. Typhoid fever and other Salmonella infections: drugs for typhoid and paratyphoid caused by sensitive strains. Gastroenteritis infection by Salmonella is generally not suitable for use. If the condition is serious, it may be optional if there is a combination of sepsis; Among adult typhoid and paratyphoid Salmonella infections, fluoroquinolones are preferred (pregnant women and children should not use this medicine). 2. Ampicillin-resistant Haemophilus influenzae type B meningitis or Streptococcus pneumoniae, Neisseria meningitidis meningitis, sensitive Gram-negative bacilli meningitis in patients allergic to penicillin, this product can be used as one of the selected drugs. Brain abscess, especially otogenic, often a mixed infection of aerobic and anaerobic bacteria. 4. Severe anaerobic infections, such as infections caused by Bacteroides fragilis, especially for lesions involving the central nervous system, can be combined with aminoglycoside antibiotics for the treatment of abdominal infections and pelvic infections to control the simultaneous presence of aerobic and anaerobic bacteria infection. 5. No other low-toxicity antibacterial drugs can replace various serious infections caused by sensitive bacteria, such as septicemia and pulmonary infection caused by Haemophilus influenzae, Salmonella and other Gram-negative bacilli, often with aminoglycosides Use together; 6. Rickettsia infection, can be used for the treatment of Q fever, Rocky Mountain spotted fever, endemic typhus.