... -positive and Gram-negative organisms, (like Streptococci, Staphylococci, Pasteurella spp., Brucella spp., Corynebacteria spp., Erysipelothrix, Coliforms, Salmonella) and Rickettsiae, Mycoplasmas, Chlamydia and some ... protozoa. Activity against Pseudomonas, Proteus- and Klebsiella spp. is low. Applied parenterally, Oxytetracycline penetrates quickly into the blood ...