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 use in livestock in its inaugural 2013 report on antibiotic resistance threats in the United States, the CDC identified resistant non-typhoidal "Salmonella" and "Campylobacter" as "serious threats" and called for improved surveillance and intervention in food production moving forward. There are other bacteria as well, where research is evolving and revealing that bacterial resistance acquired through use in livestock may be contributing to disease in humans. Examples of these include Enterococcus (including "E. coli" 0157) and "Staphylococcus aureus". For foodborne illness from "E. coli", which is still not typically treated with antibiotics because of associated risk of renal failure, increasing rates of antibiotic-resistant