streptomycin, antibiotic produced by soil bacteria of the genus Streptomyces and active against both gram-positive and gram-negative bacteria (see Gram's stain), including species resistant to other antibiotics, e.g., 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.

Antibiotic synthesized by the actinomycete Streptomyces griseus, found in soil. It was among the first antibiotics discovered (1943, by Selman Waksman), after penicillin, gramicidin, and tyrocidine. The first antibiotic effective against tuberculosis, it interferes with the tubercle bacillus's ability to synthesize certain vital proteins. It still has some use in combination with penicillin for treating endocarditis and with tetracyclines in the treatment of plague, tularemia, and brucellosis.

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