Gentamicin is an aminoglycoside antibiotic that acts bactericidal against some gram-positive and most gram-negative bacteria, such as: Staphylococcus aureus, Streptococcus spp., Escherichia coli, Salmonella spp., Pseudomonas aeruginosa, Pasteurella multocida, as well as mycoplasma. Gentamicin exhibits antimicrobial action by inhibiting protein synthesis in the ribosomes of microorganisms.