The antibacterial spectrum of oxytetracycline is similar to that of tetracycline, mainly effective against Gram positive bacteria, negative bacteria, Chlamydia trachomatis, actinomycetes, and spirochetes, but not significantly against typhoid bacteria. Therefore, oxytetracycline is mainly used for dysentery, trachoma, conjunctivitis, and pneumonia. In addition, oxytetracycline also has certain inhibitory effects on chlamydia, Klebsiella pneumoniae, Mycoplasma, spirochetes, etc.