On the rows of shelves in the laboratory, a large number of glass culture vessels are neatly arranged, with labels attached to them: streptococcus, staphylococcus, anthrax, Escherichia coli and so on. These are all poisonous bacteria. Fleming collected them in order to find a way to subdue them and cultivate them into nontoxic bacteria. In particular, one of the bacteria that looks like a grape ball under the microscope is very widespread and harmful. Wound infection and suppuration is "causing trouble". Fleming tried all kinds of drugs, trying to find an ideal drug to kill it, but never succeeded.
Before Fleming came to the shelf, he looked at the changes of bacteria in the culture vessels one by one. When he came to an incubator near the window, he frowned and said to himself, "Oh, what's the matter!" " It turned out that the culture medium in this incubator labeled with staphylococcus was moldy and a blue mold flower grew.
His assistant rushed over and said, "This is contaminated by miscellaneous bacteria. Don't use it again. Let me pour it out. " Fleming didn't give the incubator to his assistant at once, but observed it carefully for a while. To his surprise, a small circle of blank area appeared around the cyan mold, and the original staphylococcus disappeared. Did this Penicillium secretion kill Staphylococcus?
Thinking of this, Fleming excitedly put it under the microscope for observation. It was found that all the staphylococci near Penicillium had died, leaving only a little withered shadow. He immediately decided to put Penicillium into the culture medium for culture.
After a few days, Penicillium obviously increased. So, Fleming conducted an experiment: dip a thread with water-soluble staphylococcus and put it in the incubator of Penicillium. A few hours later, all the staphylococci died. Then, he separated the lines from diphtheria, pneumonia, streptococcus and anthrax, and these bacteria also died quickly. However, if you put typhoid bacteria and Escherichia coli in a line, these bacteria will still multiply.
In order to test the killing ability of Penicillium to staphylococcus, Fleming diluted Penicillium culture solution with water, first diluted it twice, then diluted it twice ... and finally diluted it with 800 times of water. Therefore, its ability to kill staphylococcus and pneumonia still exists. This is the most powerful bactericidal substance discovered by human beings at that time.
But is this Penicillium liquid harmful to animals? Fleming carefully injected it into the blood vessels of rabbits and then watched their reactions nervously. As a result, he found the rabbit safe and sound without any abnormal reaction. This proves that this Penicillium liquid is not toxic.
1June, 929, Fleming published his findings in a paper. He called this bactericidal substance secreted by Penicillium penicillin.
People congratulated him. A British dignitary suggested that he apply for a patent right to manufacture penicillin, so that he would make a fortune in the future. After consideration, Fleming wrote a letter and politely rejected the powerful man's suggestion. He said: "I can't bear to endanger the lives of countless people for the honor and wealth of myself and my family."
Fleming's discovery of penicillin seems accidental, but it is the inevitable result of his careful observation. Unfortunately, penicillin could not be used for clinical treatment at that time, because the content of penicillin in penicillin culture solution was too small, and it was difficult to extract enough penicillin for treatment. If its culture solution is directly used to treat diseases, it is actually impossible to inject thousands or even tens of thousands of milliliters at that time. Therefore, Fleming had to temporarily stop the cultivation and research of penicillin. But his discovery opened the way for later scientists.
It was 1940. Flory, an Australian pathologist in charge of pathological research at Oxford University, carefully read Fleming's paper on penicillin and became interested in this substance that can kill many kinds of germs. But he knew that Qi Xin, a scientist from all walks of life, was needed to extract this substance. He invited some biologists, biochemists and pathologists to form a joint experimental group. Among them, the German biochemist Ernst Boris ernst boris chain is his main right-hand man.
Under the leadership of Frauli, the joint experimental group carried out research and development nervously. Bacteriologists have to prepare dozens of tons of culture solution every day, pour it into culture bottles, inoculate Penicillium strains in them, and then put it into large tanks after it is fully propagated, and then send it to Ernst Boris Chain Company for refining.
The refining work is arduous and difficult, and only a small amount of penicillin can be extracted from a large pot of culture solution. After several months' efforts, Ernst Boris ernst boris chain extracted a spoonful of penicillin. Dissolve in water to kill staphylococcus, and the effect is good. Even if it is diluted by 2 million times, it still has the ability to kill.
The combined experimental group selected 50 mice for the experiment; Each of them was injected with the same amount of streptococcus, which was enough to kill them, and then 25 of them were injected with penicillin, and the other 25 were not injected. As a result, all the mice that were not injected with penicillin died, and only one mouse that was injected with penicillin died.
Subsequently, they began to extract more diligently, and finally got the penicillin needed to save a patient and saved a patient. Proved the unparalleled curative effect of this medicine.
Flory clearly realized that if penicillin is to be widely used in clinical treatment, it is necessary to improve the equipment and carry out large-scale production. But this is still impossible for the joint experimental group. Moreover, at that time, London was often bombed by German planes, and mass production was not safe.
1941June, despite the opposition of Ernst Boris ernst boris chain, Flory came to the United States with samples of penicillin unaffected by the war. He immediately began to cooperate with American scientists. Thanks to the cooperation of Qi Xin, we finally made the production equipment with corn juice as the culture medium at 24℃. Penicillin extracted from it has high purity and high yield, and soon began to be widely used in clinic. The mortality rate of some infectious diseases has dropped greatly, and countless lives have been saved.
1845, Fleming, Flory and Qian En won the Nobel Prize in Physiology and Medicine for their outstanding contributions to the discovery and utilization of penicillin.