Tetracycline antibiotics. This product is a broad-spectrum antibacterial agent. Many Rickettsia, Mycoplasma, Chlamydia, and Spirochete are sensitive to this product. Enterococci are resistant to it. Others such as Actinomycetes, Bacillus anthracis, Listeria monocytogenes, Clostridium, Nocardia, Vibrio, Brucella, Campylobacter, Yersinia, etc. are also sensitive to this product. Due to the widespread use of oxytetracycline and tetracyclines over the years, common clinical pathogens have serious resistance to oxytetracycline, including Gram-positive bacteria such as Staphylococcus and most Gram-negative bacteria. There is cross-resistance between this product and different varieties of tetracycline antibiotics. The mechanism of action of this product is that the drug can specifically bind to the A position of the 30S subunit of the bacterial ribosome, inhibit the growth of the peptide chain and affect the synthesis of bacterial proteins.

This product is a medium-acting sulfonamide. It has antibacterial effects on non-enzyme-producing Staphylococcus aureus, Streptococcus pyogenes, Streptococcus pneumoniae, Escherichia coli, Klebsiella, Salmonella, Shigella and other Enterobacteriaceae, gonococci, meningococci, Haemophilus influenzae. In addition, it also has antimicrobial activity against Chlamydia trachomatis, Nocardia asteroides, Plasmodium and Toxoplasma in vitro. The antibacterial activity of this product is the same as that of sulfamethoxazole. However, in recent years, bacterial resistance to this product has increased, especially Streptococcus, Neisseria and Enterobacteriaceae. Sulfonamides are broad-spectrum antibacterial agents. This product is similar in structure to para-aminobenzoic acid (PABA), and can compete with PABA on dihydrofolate synthase in bacteria, thereby preventing PABA from being used as a raw material to synthesize folic acid required by bacteria, reducing the amount of metabolically active tetrahydrofolate, which is an essential substance for bacteria to synthesize purine, thymidine and deoxyribonucleic acid (DNA), thereby inhibiting the growth and reproduction of bacteria.