Louis Pasteur: The Revolutionary Scientist

Louis Pasteur is the most influential in terms of comprehension of disease of the entire time frame as he is truly a giant in medicine. He was born on December 27, 1822, and he would die on September 28 1895. He was a revolutionary chemist and microbiologist. His work achieved an unprecedented advanced in science and medicine to the point that 30 institution and many streets, hospitals and schools carry his name and honour few have.

He would start his early career at the royal college of Besancon where he would gain a bachelor of science degree. From there he joined a teachers college where he would gain both his master in sciences and doctorate in the same area. Soon after he became a university chemistry professor. His first contribution to sciences was molecular asymmetry. However, sadly this discovery has no relation to the topic being explored in the book. But this fascinating discovery was based that chemical compounds reacted different to polarized light based on the different shapes in crystals of the compound and that they tended to be asymmetrical. It is a fascinating yet complex discovery that would take too long to explain however it is highly recommended to research it. Dr Pasteur's first discovery that was related to disease prevention was the Germ theory of fermentation. He made this amazing discovery while working as university chemistry in the science faculty of Dean, thanks to the request of the local brewers to help them with problems related to alcohol production in the local distillery.

Thanks to these he began deep research in alcohol fermentation. This lead to him making an amazing discovery that would lead him to study lactic acid in milk and the fermentation of some acids mainly butyric acid. Thanks to these he left for Paris in 1857 both to become manager of the Ecole Normale Superieure but most important to present a new theory. He presented scientific evidence on how fragmentation occurred thanks to microorganisms and each liquid that could fermentate had a specific one using the examples of alcohol milk and acids.

Thanks to these evidence the Germ Theory Of Fermentation was accepted fastly in the scientific community. However, these discoveries wouldn't stop there as Pasteur would go deeper into the process that made things fermentate. In this research, he discovered that the specific organisms that made fermentation could only work in the absence of oxygen. With these in mind, he created two terms anaerobic and aerobic to classify organisms that could function with oxygen (aerobic) and organisms that could only live in the absence of oxygen (anaerobic). Armed with this knowledge Pasteur would propose that the spoilage and putrefaction were caused by those anaerobic microorganisms. With these discoveries, he would first safe the French alcohol industry from contamination and preventing it from spreading diseases related to wine contamination.

Later on the French emperor Napoleon the third would request for him to study further alcohol contamination. Here he would discover a process used even to the modern day. When studying the wine contamination he realized that germs were responsible for the contamination. Then he decided to prevent more wine contamination that the solution was heating the wine to 55 Celsius to 60 Celsius or 130-140 Fahrenheit and then cooling the wine fast. He did this because he now comprehended that the bacteria couldn't survive such a fast change. This process is called pasteurization. Even in the modern day, it is used in nearly all liquids for human consumption these prevent that pathogenic agents could be spread by these liquids making infections related with these pathogens that in the modern day are nearly extinct thanks to these process. After these huge successes, Louis Pasteur would attempt to prove wrong the theory of spontaneous generation of putrefaction and fermentation. This theory stated that both of these processes happened spontaneously and couldn't be prevented. Pasteur decided that while such theory existed the progress of sciences would be stuck with pointless debates on the topic by naturalists against the scientific community.

To solve the problem he would perform a simple experiment he would deposit a piece of beef broth in a flask with a long neck that traped contaminated particles before reaching the main part of the flask, he would then heat the flask containing the broth in order to sterilize it. Then he would break the neck of the flask and as it was being exposed to air and the normal environment it would eventually show signs of bacterial contamination, and then showing that if the neck of the flask was never broken these wouldn't occur. These settled the dispute as it was clear that there was no such thing as spontaneous generation, these discovery had many implications, first it settled a 200 year dispute between naturalists and scientific researchers, second it began a peak in the use of pasteurization by both local and nationwide industries to increase the safe consumption of their products third it solidify the claims of the science of bacteriology of how microorganisms were responsible for multiple processes. However, Pasteur would make more discoveries that helped medicine.

After this discovery, Pasteur's renown incremented incredibly these lead to silkworm farmers, and a former teacher and friend to call for his aid during the silkworm crisis. This crisis consisted of a mysterious disease that caused eggs to die or silkworms to die before producing silk, these had spread to all of Europe which placed in the brink of bankruptcy. Despite him not knowing anything about silkworms, he accepted the call for aid to learning more about infectious diseases. He would dedicate the next 5 years of his life to this investigation. He would first spot that the disease could start with a mature month laying disease eggs, he suggested to the farmers to check each month that laid eggs for a specific globule in the blood or skin that he associated with the disease and if the moth had globules the eggs she had laid had to be destroyed as soon as possible. However, this didn't work healthy moths still produced diseased eggs. Facing such a mistake made him immediately return to work in finding a solution, he found sick worms without the globules and healthy ones with globules. After months and months of research, he discovered there was a second disease with a different globule, with this knowledge he managed to destroy the moth illness. However more importantly he discovered how this globule could be passed to a healthy worm by a sick one if they ate from the same leaves and the second disease passed through the intestines of worms. As well how the disease was allowed to survive by the atmospheric conditions of the worm's habitat.

Thanks to these not only precautions in the rase of livestock were made also more sanitation and consideration were adopted by humans to prevent the spread of diseases, like washing clothes and not consuming the same food another person was consuming. As well this case was what made Pasteur dedicate so much to understanding infectious disease and treating them. As well these experience and the fermentation experiments are often mentioned as the inspiration for the germ theory of disease. The germ theory was very similar to the germ theory of fermentation, it basically stated that every disease had a microorganism related to it that caused the illness process. However in the early 70s while Pasteur was an associate member of the académie de médecine the academy rejected his germ theory in favour of the miasma theory or other alternatives that were more idealistic than Pasteur's theory basically because it originated from a chemistry perspective something many doctors disagree with back on the 19th century. However, Pasteur would prove his theory not by deviating with the members but by creating an innovation that is still used today. He would create one of the first recorded efficient vaccines. His first vaccine would be against a disease known as chicken cholera. This discovery was made by observing how the lab made cultures of the microorganism that caused the disease lost their tenacity but retained reduced characteristics of the diseases over many generations. Then he injected chickens with the now weaker form of the illness to then inject them with the natural form of the disease and showed how they were totally immune.

This showed how germ theory was correct because it demonstrated that if the specific microorganism was unable to survive in the body (in these case thanks to the chicken being immune) the disease would not be present either its symptoms. After these, he worked on anthrax. At the same time, Robert Koch had discovered and isolated the anthrax bacillus (the causant of the anthrax infection) and announced the life cycle of the disease. Pasteur confirmed these discoveries being the truth. After these, he would provide evidence that the bacillus was fully responsible of the disease, through the use of injecting it to healthy sheep and watching how the disease was contracted and symptoms appear by the previously healthy sheep and by observing how all disease sheep had the bacillus in their body. These combined with other evidence provided by Koch of the life cycle of anthrax forced medicine to accept the germ theory of disease and abandon the Miasma theory of disease and the science of medical microbiology was born. As well for removing any doubt of germ theory being wrong he began to work in a vaccine against anthrax. He would first determined what weakened the virus for making it is less severe. Then thanks to financial support of the farmers 70 to 80 farm animals were made successfully immune to the disease. Then Pasteur would take the immune sheep and normal sheep to inject them with the natural form of the bacillus, after 2 weeks all normal sheep were death meanwhile all vaccinated sheep were completely healthy and no symptoms of anthrax had appeared.

This was the final evidence on how the disease was indeed caused by a specific microorganism as well that vaccines were an effective way of immunization (despite the belief of some modern parent unions and politicians). After these Pasteur dedicated part of his life to investigating where these microorganisms came from making him the pioneer of pathology. His research in this area is incredible however it is not on the topic of the book yet it's worthwhile researching it. After finishing his research on the origin of the organisms, he would decide to attempt the creation of a vaccine for rabies. Rabies was a terrible disease to the point that in some rural areas it was a horror story, the disease caused pain in the muscles fever, loss of appetite, hallucinations, fear, coma and an aggressive behaviour that often was treated by cauterizing the wound that had transmitted the disease (this, of course, did absolutely nothing to prevent it.

However unlike anthrax, chicken chole and the moth diseases Pasteur had faced the microbe was too little to be seen by a microscope, so he had to develop several new techniques. First, he attempted to create a stable sample by giving it to multiple rabbits. Once he thought he had the stable sample he tried to create the less severe version of the virus, by desiccated the spinal cords of the infected rabbits, however, he didn't know that he had actually neutralized it effectively creating a whole new kind of vaccine an inactivated vaccine. An inactivated vaccine is a vaccine that uses viruses, bacteria or other microorganisms that have been grown in culture and then killed for generating immunity in the body. Here sources disagree if Pasteur actually knew this some say that he would, later on, comprehend it, others that he had no idea what he had done and it was a coincidence and others that he had planned it to be this way. However, if he did knew what he had done or not he proved his creation in a historic day July 6 1885, the day someone survived rabies and lost the disease for the first time in recorded history.

Pasteur had learned from some contacts in Paris of a young 9-year-old boy named Joseph Meister that had been bitten by a rabid dog and was showing early symptoms of the disease. Pasteur would inject great quantities of his creation on a daily basis for 1 to 2 weeks. The vaccine was successful, the kid recovered from the disease nearly immediately. However, the reason this had been so hard to achieve was that rabies is not caused by a bacteria or germ the responsible microorganism for rabies was something unknown to both Pasteur and Koch a virus. A virus is a non-living (as it does not fulfil the requirements of the scientific community of growing and reproduction). These, of course, was the cause of it being too small for Pasteur's microscope and why it became neutralized instead of weakened, and this term wouldn't be discovered until our next individual did his contribution in 1892, Willem Beijerinck. Yet sadly these would be Pasteur last achievement as he would die at the age of 72 by paralysis that had afflicted him the past years of his life The implications of Pasteur's work were many as he discovered and innovate many concepts and theories.

The most prominent impact he had in society was the prevention of diseases. As in the times of Pasteur's creations there was nothing to do about diseases in terms of prevention apart from avoiding physical contact with the disease, of course, this changed with Pasteur and many were vaccinated against this diseases that he produced vaccines against and as he had created the methodology and Koch had perfected it many vaccines began to appear against many diseases. These were his maximum legacy as many that would have died by know are still alive thanks to the vaccines. And as no one thought vaccines had a negative impact much less that it created autism many kids were vaccinated against these diseases. Another impact he had in society was leaving tons of methods for creating vaccines and microorganism investigation. Were used and are still used in the creation of vaccines and the inquiry of microorganisms. That the institution that carries his name would teach and used. As well he marks the beginning of the new era of prevention and longer life spans. And his contribution to society was so big that he would be buried in the Notre Dame cathedral and be awarded the legión of honour and commemoration was done in the newspaper when he died an honour that back then was limited to kings, queens, aristocracy and other members of high society. However, it is worth mentioning that Pasteur is the most persevering of the entire individuals to contribute to medicine in the entire history. He never accepted defeat and just reading it might the reality of these be lost. As what has just been described is his success however these important contributions were the result of trying and failing. And when others would have simply given up after such failures.

For example, in the silkworm diseases many would have given up after failing the first time but he instead and dedicated 5 years of his life to solving the problem. As well all of his life he discussed with those who thought that miasma was correct or that disease happened spontaneously or other sceptics of his work. He is really a fascinating individual that is worthwhile learning about.