Louis Pasteur, born on December 27, 1822, in Dole, France, and died on September 28, 1895, Saint-Cloud, was a French chemist and microbiologist who was one of the most important founders of medical microbiology. Pasteur’s contributions to science, technology, and medicine are nearly without precedent. He pioneered the study of molecular asymmetry; Louis Pasteur discovered that microbes were responsible for souring alcohol and came up with the process of pasteurization, where bacteria are destroyed by heating beverages and then allowing them to cool and saved the beer, wine, and silk industries in France; His work in germ theory also led him and his team to create vaccinations for anthrax and rabies. Louis Pasteur was a chemist and microbiologist whose work changed medicine.
Many scientists in the world have selflessly served humanity. They have saved the lives of millions of people through their hard work day and night. One such selfless scientist was scientist Louis Pasteur.
Rabies was one of the worst diseases of the time. Evidence of this has also been found in various cave paintings discovered so far. When Louis Pasteur invented the rabies vaccine for this ancient disease in 185, the world's population was about 1.5 billion. Out of these 1.5 billion, about one crore people were infected every year by the bites of animals such as dogs, rats, foxes, and bats. The rabies vaccine discovered by Pasteur has freed mankind from this terror. However, this discovery was not possible overnight; It also has a long history behind it.
1822, A poor leather merchant in a village in France was remorseful, "alas! if I had studied, I probably wouldn't have had to spend the day cleaning dirty and smelly skin today." Suddenly he heard the news that a son had come across the lap of his pregnant wife. On hearing this news, he happily decided that even if he could not read by himself, he would educate his child in higher education. This businessman was the proud father of the scientist Louis Pasteur, Jean-Joseph Pasteur.
At 9 years old, he was admitted to the local secondary school where he was known as an average student with a talent for art and singing. However, he was very diligent, often helping him with his father's work in addition to his studies.
When he was 16, Pasteur traveled to Paris to continue his education but returned home after becoming very homesick. He entered the Royal College at Besançon where he earned a Bachelor of Arts. He stayed to study mathematics but failed his final examinations. He moved to Dijon to finish his Bachelor of Science. In 1842, he applied to the Ecole Normale in Paris, but he failed the entrance exam. He reapplied and was admitted in the fall of 1844 where he became a graduate assistant to Antoine Ballard, a chemist and one of the discoverers of Bromine.
Pasteur secured his academic credentials with scientific papers on this and related research and was then appointed in 1848 to the faculty of sciences in Strasbourg. While in Strasbourg, Pasteur began studying fermentation. His work resulted in several improvements to the industries of brewing beer and making wine. In 1854, Louis accepted a position at the University of Lille, where he was asked by a local tradesman to help find out why some of the casks of fine vinegar made from beet juice were spoiling. Pasteur examined the good vinegar and the spoiled vinegar under the microscope. He knew that the yeast that caused the beet juice to ferment was a living organism. Casks producing good vinegar contained healthy yeast while those producing the spoiled product also contained microscopic rods that harmed the yeast.
Pasteur hypothesized that these small “microbes” were also living organisms that could be killed by boiling the liquid. Unfortunately, this would also affect the taste of the vinegar. By careful experimentation, he discovered that the infecting microbes could be killed by controlled heating of the vinegar to 50-60 degrees Celsius (122-140 degrees F) and then rapidly cooling. Today the process is known as pasteurization.
As Pasteur learned more and more about bacteria, he began to think they may be the cause of disease in humans. When the French silk market was threatened by disease to silkworms, Pasteur decided to investigate. He discovered that this disease was caused by microbes. By eliminating the microbes from the silkworm farms, he was able to end the disease and save the French silk business.
By the early 1870s, Pasteur had already established himself as a renowned leader in research, and in 1877 Pasteur began to fully immerse himself in the study of disease. At the time, Pasteur was studying chicken cholera (Pasteurella multocida), a diarrhoeal disease that was destroying the breeding chicken population. Influenced by Edward Jenner, Pasteur reasoned that if a vaccine could be found for smallpox, vaccines could be found for all diseases.
By 1878, Pasteur had succeeded in culturing the causative virulent bacteria of chicken cholera and began inoculating chickens. However, many chickens died after the procedure so Pasteur continued to study the disease, looking for safer inoculation methods. It was during this study that Pasteur changed the field of virology forever.
In 1879, Pasteur observed, by chance, that old bacterial cultures lost their virulence. He had instructed an assistant to inject the chickens with a fresh culture of the viral bacteria before a holiday. The assistant, however, forgot and went on vacation. When he returned a month later, he performed the procedure using the old cultures. Unexpectedly, the chickens only showed mild signs of the disease and survived. When they were healthy again, Pasteur, intrigued by the results, injected them with fresh bacteria. The chickens did not become ill. Pasteur reasoned the factor that made the bacteria less deadly was exposure to oxygen.
The discovery of the chicken cholera vaccine by Louis Pasteur revolutionized work in infectious diseases and can be considered the birth of immunology. The notion of using a weakened form of the disease to provide immunity was not new, but Pasteur was the first to take the process to the laboratory, impacting all virologists who followed after him.
Louis Pasteur was actively pursuing his research. He wondered if the process by which the body of the chicken developed immunity would be effective against other diseases or other animals as well. Maybe! If other diseases are caused by germs, then certain germs are also responsible for rabies. And if you can control this germ, maybe you can make an antidote for rabies. His idea was right again. He also invented the rabies vaccine using the same theory. Pasteur was understandably reluctant to test his treatment on human beings. Since he still could not see the microorganism that caused the disease, he had only experimental data to show that drying attenuated the causative agent. What if he injected a human being and caused a person to contract rabies?
On July 6, 1885, an emergency forced Pasteur to act. Nine-year-old Joseph Meister had been bitten repeatedly by a rabid dog. The situation was grave, the boy was certain to develop rabies and die horribly unless Pasteur treated him successfully. Pasteur reluctantly agreed to administer the painful treatment. Despite his misgivings, Pasteur’s vaccinations proved successful and Joseph Meister made a complete recovery.
Pasteur began investigating anthrax in 1879. At that time an anthrax epidemic in France and some other parts of Europe had killed a large number of sheep, and the disease was attacking humans as well. German physician Robert Koch announced the isolation of the anthrax bacillus, which Pasteur confirmed. Koch and Pasteur independently provided definitive experimental evidence that the anthrax bacillus was indeed responsible for the infection. This firmly established the germ theory of disease, which then emerged as the fundamental concept underlying medical microbiology.
Pasteur wanted to apply the principle of vaccination to anthrax. He prepared attenuated cultures of the bacillus after determining the conditions that led to the organism’s loss of virulence. In the spring of 1881, he obtained financial support, mostly from farmers, to conduct a large-scale public experiment of anthrax immunization. The experiment took place in Pouilly-le-Fort, located on the southern outskirts of Paris. Pasteur immunized 70 farm animals, and the experiment was a complete success. The vaccination procedure involved two inoculations at intervals of 12 days with vaccines of different potencies. One vaccine, from a low-virulence culture, was given to half the sheep and was followed by a second vaccine from a more virulent culture than the first. Two weeks after these initial inoculations, both the vaccinated and control sheep were inoculated with a virulent strain of anthrax. Within a few days, all the control sheep died, whereas all the vaccinated animals survived. This convinced many people that Pasteur’s work was indeed valid.
In 1873, Pasteur was named a fellow in the French Institute of Medicine. In 1888, the French government allocated funds for the establishment of the Pasteur Institute in Paris, where he continued his research and served as dean of science. In 1895, while still working part-time at his lab, he suffered the first of a final series of strokes. Louis Pasteur died on Sept. 28, 1895. His last words were, “One must work; one must work, I have done what I could.”
Interesting Facts about Louis Pasteur -
1. Early on in his career Pasteur studied crystals and discovered why some crystals bend light while others do not.
2. He was a deeply religious Christian throughout his life.
3. Pasteur's ideas on micro-organisms causing disease eventually led to the boiling of surgical instruments helping to prevent infections and causing many people to survive the surgery.
4. He once said that "In the field of observation, chance favors the prepared mind."
My humble tribute to the father of microbiology.