Pasteur, Koch and Lister - Germs!

I hope you've never come face to face with food which is as rotten as this. But if you could bear to look at it really closely, through a microscope say, this is what you might see. We now know these are tiny living things, microorganisms. And we understand how certain kinds of them were involved in processes like decay and disease. But as little as 150 years ago, scientists were hotly disputing what they were and where they came from. So what happened about that time to make our understanding clearer? The answer lies partly with three great men. The first, a Frenchman, Louis Pasteur, was a professor of chemistry. The second, an Englishman, Joseph Lister, was a surgeon. And the third, a German, Robert Koch, was a doctor. If you shuffle cards around, you get different combinations. Put one on top of the other, and you can get a bigger score. And if you have an ace, that usually gives you a better score still. Pasteur, Lister and Koch held several aces. I'm going to call them industry, government, nationalism, communication, technology, war, chance, and of course, money. Let's begin with industry. By 1854, the French government was becoming aware how valuable science could be to industry. It appointed Pasteur, who already had a great reputation as a chemist, to be professor at a new scientific college in an important industrial area. A local brewer was having problems. The fermentation, which was supposed to be going on inside the vats, wasn't working. So the alcohol wasn't forming properly. He had asked for Pasteur's help. Please. After a careful series of experiments, Pasteur found the explanation. It's harmful microorganisms in the vats which are causing all the trouble. Leave the matter with me. I'm sure a solution can be found. Thank you, monsieur. But there were wider implications. Everything indicates that contagious diseases owe their existence to similar causes. And Pasteur's work would not only shed light on disease, but would contribute to the debate about what was known as the theory of spontaneous generation. In the middle of the 19th century, not all scientists saw microorganisms in the same light. It was known that you could find microorganisms wherever processes like decay, disease and fermentation were taking place. But some scientists believed that these living things could appear spontaneously, as if from nowhere. Others, like Pasteur, argued that they must have got in from outside, carried, for example, on the dust particles in the air. Pasteur wanted conclusive proof that he was right. But for a long time, he couldn't work out how to keep the dust away. Then, an elderly professor came to his aid. Suppose I boil liquid and leave it to cool. After a few days, mouldiness, little animals will develop in the liquid. By boiling, I destroy any germs, but the liquid being again in contact with the air will change and become mouldy. Now, suppose that before boiling the liquid, I draw the neck of the flask into a point, leaving its end open. Then I boil the liquid in the flask and leave it to cool. The liquid will remain pure, not only for two days, a month, a year, but two or three years. What difference is there then between these two flasks? In the first, the dusts suspended in the air and their germs can fall into the flask and arrive in contact with the fluid. In the second, the dust falls on its curved neck or into the first curve only. The one thing that cannot enter easily is the dust suspended in the air. The proof of this is that if I shake the flask violently two or three times, in a few days, it will contain little animals or mouldiness. Why? Because air has come in violently enough to carry the dust with it. And never will the doctrine of spontaneous generation recover from the mortal glow of this simple experiment. When it had been shown by the researchers of Monsieur Pasteur that the poisonous property of the air depended on minute organisms suspended in it, it occurred to me that the infection of the wounds might be avoided by applying, as a dressing, something capable of killing these floating particles. That was Joseph Lister, an English surgeon, writing in 1867. For years he had been worried about the high death rate of patients whose wounds turned septic after operations. So when a colleague, a professor of chemistry, told him about Pasteur's work, he seized on the idea that microorganisms might carry infection. Fill the reservoir with carbolic acid, please, Mr. Leeson. If he could kill them, he might prevent wounds from becoming infected. He knew carbolic acid had recently been used to make sewage safe as a fertiliser. Did it work by killing microorganisms? And if so, would it work for patients? From 1865, he experimented in different ways, including inventing a carbolic spray. Turn on the spraying mechanism, please, Mr. Leeson. The whole scene of the operation or dressing was enveloped in this spray. It went into every nook and cranny of the wound. Our faces and coat sleeves often dripped with it. Needless to say, the carbolic acid made sad work of our hands, which were always rough and cracked. Carbolic acid had its dangers, but Lister was on the right lines. In a few years, the death rate from operations had gone down spectacularly. Lister's success was partly due to fast communication of scientific ideas and partly to new technology. Meanwhile, what about Pasteur? He had suffered great personal tragedy with the death of his father and last two daughters in quick succession. He himself had had a stroke which had left him half paralysed. Did that heighten his interest in human disease? It may have done, but in the meantime, the French government had already asked him to look into the diseases of the wine industry, as well as the death of silkworms, which were costing the French wine and silk industries millions of pounds a year. Fine, but while other industrial nations like Germany were pouring money into applied science to help industry, France lagged behind. And Pasteur had begun a campaign to get more money for French research. And then... Franco-Prussian war broke out. The Prussians were better led, better organised and better equipped than the French. French casualties were enormous. Pasteur's only son was among the wounded. He went out to search for him. Pasteur never forgot this war. Hatred of Prussia. Revenge. On the German side, there was a young doctor called Koch. He gained first-hand experience of battle wounds and fever. After the war, he returned home as district medical officer, with particular responsibilities for public health. Koch had set up a laboratory in his home, at his and his family's own expense. In this remote country area, there was an outbreak of anthrax, a disease which decimated sheep and cattle and occasionally infected humans. Koch, who had developed a special interest in microscopes, decided to investigate. His research built on the work of Pasteur and Lister on microorganisms. One feature of anthrax was that cattle could catch it not only from other infected cattle, but also from the soil where the infected animals had grazed. Koch showed that this was because the type of microorganisms or bacteria responsible for the disease could exist in the soil as particularly hardy forms known as spores. We see that anthrax tissues, whether they're fresh, rotting or years old, produce anthrax when these tissues are capable of developing spores of Bacillus anthracis. When these spores are once formed in the soil, there is good reason to believe that anthrax can remain in this region for many years. Knowing this, we must now seek measures in order to save the animals and to protect thousands of people from an agonizing death. Technology had helped Koch's breakthrough. But that's where Pasteur moved in. France too lost many sheep and cattle to the anthrax disease. So Pasteur, always a nationalist, decided to help France and go one better than Germany by trying to get rid of the anthrax. By now, he had government backing and money to form a team of vets and doctors. His first aim was to work out in detail how the anthrax was transmitted. To do this, they had to grow the microorganisms or germs in a culture and inject them back into animals to prove that this particular kind of germ was the sole cause of the disease. In 1878, they discovered that a sheep that had had anthrax and recovered couldn't catch it a second time. This discovery paralleled an earlier one by the English, who had found out how to vaccinate people against the terrible disease of smallpox. Pasteur didn't understand any more than they did how it worked, but he realized it was a very important discovery. The search for a vaccination against anthrax was on. And then, chance came to Pasteur's aid. His team were using chickens in their anthrax work. Chickens suffered from a disease called fowl cholera, and now they were asked to investigate that. Once again, they tried growing a culture of germs and injecting them. One day, Charles Chamboulon, his assistant, happened to use an old culture, which had been standing in the air, to inoculate some chickens with. In theory, the chicken should have died. In fact, it continued to be alive and healthy. So Chamboulon decided there was something wrong with the culture, and he went to throw it away. One moment, Monsieur Chamboulon. Pasteur had one of his flashes of genius. We should make a new culture of the germ and inject it into this same bird. Once again, the chicken survived. It only remains for us to satisfy ourselves that this new culture truly is virulent. But when Pasteur had a new lot of chickens injected with the new culture, they died. Pasteur had guessed that exposure to the oxygen in the air had caused the germs in the culture to become weak. He and his team did more experiments, and proved without doubt that the germs were weakened in this way. If a chicken was vaccinated with these weakened germs, the bird became immune from the disease. So they applied this technique to the germ which caused anthrax. And when they were sure they had the answer, Pasteur staged a public demonstration. By telegraph from the Times correspondent. On the 5th of May, 25 sheep were inoculated with a weakened form of the anthrax bacillus. Later, on the 31st of May, these 25, together with a further 25 sheep, were inoculated with the strongest form of the germ. Monsieur Pasteur predicted that the 25 sheep not previously inoculated would die. But the previously inoculated sheep would show no symptoms of sickness. A number of spectators came together to witness the results. At 2 o'clock, 23 of the sheep which were not previously inoculated were dead. The 24th died at 3 o'clock, and the 25th an hour later. The other 25 animals gave signs of perfect health. While Pasteur was making and publicising these obviously useful discoveries, Robert Koch quietly continued to develop techniques to prove that each disease was caused by one specific germ. His assets were his own personal interest in technology, backed by new industrial processes which made his work easier. After his work on anthrax, he worked hard to obtain better images of bacteria. He developed a way to stain them, so he could see them more clearly, using special dyes developed for industry. An interest in photography led him to develop techniques for photographing bacteria down a microscope. Next, to isolate one particular kind of germ, he used a solid substance, rather than Pasteur's liquids, to grow it on and study it. And to do this, he first used the humble potato. Some people think that using a solid substance to grow germs on was one of the most important technical discoveries ever. Soon, the German government offered him a job as advisor on health with a laboratory and assistants in Berlin. Here, he perfected the technological basis of modern bacteriology. He identified particular germs which infected patients after surgery, so he was able to show how Lister, remember him? Had been so successful with his ideas of killing germs. In 1881, an important international congress was held in London. It brought together Lister, Koch, and Pasteur, as well as many of their opponents. Invitations were sent out to 120,000 people, and lots of important people outside the medical or scientific world attended. They heard and saw the arguments which finally knocked the idea of spontaneous generation on its head. An old opponent of both Pasteur and Lister's still denied that germs existed outside the body, and attacked Lister's methods of fighting disease with antiseptic sprays. Mr. Chairman, sir, I speak on my French colleague's behalf. Monsieur Pasteur invites Mr. Bastien to take an animal's limbs, to crush them and allow blood to form around the bones, taking care that the skin is not open to the air in any way, and defies Mr. Bastien to find any microorganism forming spontaneously within the limbs. Later, Lister invited Koch to show and illustrate the new techniques which would enable future researchers to track down germs. Congratulations here, doctor. Excellent piece of research. You have made great progress, monsieur. There's no doubt how much we've benefited by the work of Pasteur, who discovered the principle of the germ theory. Koch, who first identified bacteria responsible for causing disease, and indeed Lister, who pioneered antiseptic methods. But would they have been so successful without the benefit of other influences? Or indeed, without being able to build on each other's work?