Streptomycin Sulfate

Antibacterial spectrum: streptomycin sulfate is a narrow-spectrum aminoglycoside (but the antibacterial spectrum is wider than penicillin), mainly against aerobic Gram-negative bacteria. It has a good antibacterial effect on a variety of Gram-negative bacteria, such as Escherichia coli, Pasteurella, Salmonella, Brucella, Proteus, etc. It has poor effect on most gram-positive cocci such as Staphylococcus aureus. It has a synergistic bactericidal effect in combination with penicillin, and is also effective against Leptospira. Streptococcus, Pseudomonas aeruginosa and anaerobic bacteria are resistant to streptomycin sulfate.

The lower concentration of streptomycin sulfate is bacteriostatic, and the higher concentration is bactericidal; it is ineffective against fungi, rickettsia, and viruses. The antibacterial activity is the strongest in the weak alkaline (pH7.8) environment, and the activity decreases in the acidic (below pH6) environment. Bacteria can easily develop resistance after exposure to streptomycin sulfate, which is faster than penicillin and can reach a high level of resistance in a short period of time. Because streptomycin sulfate has been widely used in veterinary clinics for a long time, drug-resistant pathogens are widely prevalent, and there is some cross-resistance with kanamycin and gentamicin. Bacteria resistant to antibiotics and gentamicin are also resistant to streptomycin sulfate; but bacteria resistant to streptomycin are still sensitive to gentamicin and kanamycin. Most of the clinical strains are resistant to plasmid-encoded enzymes, and the streptomycin resistance genes on the plasmids are often linked to sulfonamide, ampicillin and tetracycline resistance genes. Therefore, streptomycin sulfate is often combined with other antibacterial drugs to prevent pathogenic bacteria from chromosomal mutation resistance.