In 1928 a Scotsman discovered the strange effects of a specific fungi. Along with a German and an Australian this fungi was turned into a drug. On March 14th 1942 the first patient was treated with this drug.
The drug was of course Penicillin, the Scotsman Sir Alexander Flemming, the German Ernest Boris Chain, and the Australian was Baron Florey. These men made potentially the greatest contribution to modern medicine. The bacteriostatic and bacteriocidal effects of penicillin were noted long before 1928, however these men did more than just make some mildly interested notes and move on. They developed this drug. However I would suggest their achievement will only be temporary.
Since the 50's almost everyone in the western world has come in contact with penicillin. A hundred years ago if you had a minor infection you would have a fever, a headache, maybe some localised pain. You would put your feet up for a few days and your body would take care of the infection. Your immune system would be better for it as it would create markers to prevent that same bacteria having such an effect again. My generation is given pencillin and other anti-bacterial drugs for almost any complaint. Our immune systems are weaker which means we are getting sick more often. But it gets worse, our bodies are becoming resistant to the penicillin, the constant exposure is causing our immune systems to neutralise these drugs before they can have a theraputic effect. Also as I'm sure you are all aware bacteria are surviving one dose of antibiotics and what they grow back into are resistant to that anti-biotic(MRSA is the big one everyone has heard of). Once the effects of these drugs are completely useless our bodies will have a hard time even fighting a simple streptococcus infection.
We are now sending antibiotic drugs across the world to third world nations. Into jungles to near untouched tribes of humans, to places a strong immune system is vital.