Penicillin was discovered in 1928 by Scottish scientist Alexander Fleming. People began using it to treat infections in 1942. There are several enhanced penicillin families which are effective against additional bacteria; these include the antistaphylococcal penicillins, aminopenicillins and the antipseudomonal penicillins. They are derived from "Penicillium" fungi. The term "penicillin" is often used generically to refer to benzylpenicillin (penicillin G, the original penicillin found in 1928), procaine benzylpenicillin (procaine penicillin), benzathine benzylpenicillin (benzathine penicillin), and phenoxymethylpenicillin (penicillin V). Procaine penicillin and benzathine penicillin have the same antibacterial activity as benzylpenicillin but act for a longer period of time. Phenoxymethylpenicillin is less
Penicillin found in the broth filtrate. Despite this, he remained interested in the potential use of penicillin and presented a paper entitled "A Medium for the Isolation of Pfeiffer's Bacillus" to the Medical Research Club of London, which was met with little interest and even less enthusiasm by his peers. Had Fleming been more successful at making other scientists interested in his work, penicillin for medicinal use would possibly have been developed years earlier. Despite the lack of interest of his fellow scientists, he did conduct several experiments on the antibiotic substance he discovered. The most important result proved it was