Fleming named penicillin in 1929 for a mould’s antibacterial juice
Penicillins are β-lactam antibiotics first drawn from Penicillium moulds, chiefly P. chrysogenum and P. rubens. Alexander Fleming noticed the crude extract in 1928 and coined the name on 7 March 1929. Clinical purification and wartime production came later.
Eight Chrysogena-section species make natural penicillins; most clinical supply is fermented then chemically modified into broader antistaphylococcal, amino, and antipseudomonal agents. Fleming’s student Cecil George Paine treated neonatal eye infection with penicillin in 1930—an early success before mass manufacture. An Oxford group under Howard Florey and Ernst Boris Chain first extracted pure penicillin F in 1940; Fleming used purified drug against streptococcal meningitis in 1942, and the three men shared the 1945 Nobel Prize in Physiology or Medicine.
Fleming joked he named it the orthodox way, like digitalin from Digitalis: a substance from Penicillium. Modern usage covers any β-lactam with the fused thiazolidine ring, natural or not. Natural broths are mixtures; some named “penicillins” later proved inactive. Fleming's own strain made mainly penicillin F, named for him, but it is unstable, scarce and hard to isolate. Only two purified natural forms are used in clinics today: penicillin G, injected, and penicillin V, swallowed.
In the United States about ten percent of people claim penicillin allergy, yet skin-test positivity falls about ten percent per avoidance year, so most can eventually tolerate it, and many allergic patients still handle related drugs.
Penicillins were among the first drugs to beat many staphylococcal and streptococcal infections, and they remain in wide use, although heavy prescribing has bred resistance in many bacteria. For allergic patients, cephalosporins are usually a safe alternative, since antibody cross-reactivity runs at only about 3 percent.
Source: Penicillin
