Which antibiotic was the first proven effective treatment for tuberculosis?

Streptomycin was the first antibiotic proven effective against tuberculosis.

Researchers at Rutgers University discovered streptomycin in 1943, isolating it from the soil bacterium Streptomyces griseus. Clinical studies soon showed that it could improve tuberculosis, a disease that previously had no reliably effective antibiotic treatment.

The first major controlled clinical trial of streptomycin for pulmonary tuberculosis was conducted in Britain in 1948. It demonstrated benefit but also revealed that bacteria could become resistant when streptomycin was used alone.

Later treatment therefore combined multiple drugs, such as isoniazid and rifampicin, to reduce resistance. Penicillin, another famous antibiotic, is not the answer because it is ineffective against the tuberculosis bacterium in ordinary clinical use.