Discoverer of penicillin Alexander Fleming warned against its overuse and the risk of resistant microorganisms as early as 1945, in his Nobel Prize lecture

"The time may come when penicillin can be bought by anyone in the shops. Then there is the danger that the ignorant man may easily underdose himself and by exposing his microbes to non-lethal quantities of the drug make them resistant.

Here is a hypothetical illustration. Mr. X has a sore throat. He buys some penicillin and gives himself, not enough to kill the streptococci but enough to educate them to resist penicillin. He then infects his wife. Mrs. X gets pneumonia and is treated with penicillin. As the streptococci are now resistant to penicillin the treatment fails. Mrs. X dies. Who is primarily responsible for Mrs. X's death? Why Mr. X whose negligent use of penicillin changed the nature of the microbe.

Moral: If you use penicillin, use enough"

Sir Alexander Fleming shared the Nobel Prize in Physiology or Medicine in 1945 with Howard Florey and Ernst Boris Chain for his discovery of the world's first antibiotic substance benzylpenicillin (Penicillin G) from the mould Penicillium notatum in 1928. He also discovered the enzyme lysozyme in 1923.

Fleming's Nobel Lecture reached from here:Nobel Lecture by Sir Alexander Fleming on December 11, 1945

Yoshinori Ohsumi: Autophagy from begining to end

Yoshinori Ohsumi was influenced by his father, who was a professor of engineering at Kyushu University, He was familiar with academic life while he was growing up. But whereas his father worked in a very industrially oriented field, he was more interested in the natural sciences. In high school, he was interested in chemistry, so he entered the University of Tokyo to learn chemistry. He quickly discovered chemistry wasn't so attractive to him, because the field was already quite established. But he was lucky, he thinks, because the early 1960's was the golden age of molecular biology. He decided he wanted to work on that instead.

There were not very many molecular biology labs in Japan at that time. He joined Dr. Kazutomo Imahori's lab as a graduate student to study protein synthesis in E. coli. Unfortunately, he did not get very good results in his work, and, when he had finished his graduate studies, he discovered it was very difficult to find a good position in Japan. So, on Dr. Imahori's advice, he took a postdoctoral position with Dr. Gerald Edelman at The Rockefeller University in New York.

As a graduate student, he had worked on E. coli., but in Dr. Edelman's lab he switched to working on mammalian cell and developmental biology. He was supposed to establish a system for in vitro fertilization in mice,  but he did not know very much about early embryology and he had only a very small number of eggs to work with. He grew very frustrated. Then, one and a half years later, Mike Jazwinski joined Edelman's lab, and he decided to work with him instead on studying DNA duplication in yeast. That was another huge leap for him, but it was also his first introduction to yeast cells, which he has worked with ever since.

Finally, he was offered a position as a junior professor in Yasuhiro Anraku's lab at the University of Tokyo and was able to return to Japan

For complete interview, read this 2012 interview conducted by Journal of Cell Biology, where Yoshinori Ohsumi explains his progress within the field of autophagy.