Streptomycin is an antibiotic produced by soil bacteria of the genus Streptomyces and is active against both gram positive and gram negative bacteria, including species resistant to other antibiotics, eg some streptococci, penicillin resistant staphylococci, and bacteria of the genera Proteus and Pseudomonas. Originally isolated by Selman A. Waksman and Albert Schatz in 1947, streptomycin is effective against tubercle bacilli and is a mainstay of tuberculosis therapy. Because streptomycin resistant tubercle bacilli emerge during treatment, the antibiotic is usually used in combination with one or more of the drugs isoniazid, ethambutol, and aminosalicylic acid. Streptomycin acts by inhibiting protein synthesis and damaging cell membranes in susceptible microorganisms. Possible side effects include injury to the kidneys and nerve damage that can result in dizziness and deafness.