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 prophylaxis 2006 against antibiotics for growth promotion purposes. It was estimated in 2014 that over 80% of the world's antibiotic use was on farms. Coccidiosis in fowl had evolved increased tolerance to the antibiotic feed. The WHO warned in April 2014 that farm use was a contributor to superbugs in humans. The Auditor General of Canada found lack of progress in 2014 on antimicrobial resistance despite three years of government funds that should have been used to implement a reduction programme. A CBC writer was concerned that there was in Canada "no coordinated national system to control antibiotics in agriculture." Due