Antibiotic penicillin led to renewed interest in the search for antibiotic compounds with similar efficacy and safety. For their successful development of penicillin, which Fleming had accidentally discovered but could not develop himself, as a therapeutic drug, Chain and Florey shared the 1945 Nobel Prize in Medicine with Fleming. Florey credited Rene Dubos with pioneering the approach of deliberately and systematically searching for antibacterial compounds, which had led to the discovery of gramicidin and had revived Florey's research in penicillin. In 1939, coinciding with the start of World War II, Dubos had reported the discovery of the first naturally derived antibiotic,
Antibiotic gastric juices and hydrogen peroxide). It also excluded synthetic antibacterial compounds such as the sulfonamides. In current usage, the term "antibiotic" is applied to any medication that kills bacteria or inhibits their growth, regardless of whether that medication is produced by a microorganism or not. The term "antibiotic" derives from "anti" + βιωτικός ("biōtikos"), "fit for life, lively", which comes from βίωσις ("biōsis"), "way of life", and that from βίος ("bios"), "life". The term "antibacterial" derives from Greek ἀντί ("anti"), "against" + βακτήριον ("baktērion"), diminutive of βακτηρία ("baktēria"), "staff, cane", because the first bacteria to be discovered were rod-shaped. The