ABSTRACT
Prior to Fleming’s discovery of an antibacterial substance produced by the fungus Penicillium rubens* in 1929, several authors discussed the production of antibacterial substances by microorganisms and their therapeutic potential. However, all these products were either too toxic for systemic application or low in activity (e.g., pyocyanase from Pseudomonas aeruginosa [1889]). H. Florey and coworkers isolated penicillin and demonstrated its activity and innocuity in animals and humans. This led S.A. Waksman to examine his Streptomyces collection, and in 1944, his group announced the discovery of streptomycin. Others quickly followed this “natural product approach” for nding antibiotics. A chemical approach had emerged in parallel, even earlier.
