A Short History of Microbiology

Before there were computers, cars, cell phones, hospitals, even humans all together, there were microbes. Microbes have played a huge role in the history of mankind and continue to be a major player in medicine, food and drug development, and disease. Evidence of microbiology can be found in the Bible, historical Greek and Roman writings, and was the cause of the Black Plague.

The bible makes numerous references to leprosy and those who have been infected with leprosy, known as lepers. Leprosy is caused by Mycobacterium leprae and Mycobacterium lepromatosis. We know now that leprosy was a term used to cover a wide range of infectious and non-infectious diseases, but the isolation of infected individuals did slow the spread of the disease, which they figured out long before a microscope was ever available. In addition to leprosy, the plague was also referenced in the bible, as well as good sanitary practices to prevent disease.

Babylonians and Egyptians were using microbes thousands of years ago to make food products. There has been beer recipes found in 6000 year old Egyptian hieroglyphics. In modern day Iran, the earliest known records of making wine were found, dating back as far as 5000 years ago. Hippocrates was a Greek Physician in 400 B.C. that set a standard for the world of medicine. He found the various symptoms of disease and found that some diseases were contagious. During this same time, a lesser known Greek, Thucydides, found that people who got the plague and survived could care for other victims of the plague without contracting it again. The Romans also had their share of historical roots in microbiology. Varro, a Roman writer, stated that tiny animals caused disease in humans. Lucretius, a Roman poet, talked about “seeds” of disease in his famous work On The Nature of Things, or De Rerum Natura.

The bubonic plague has been the cause of death for millions of people around the world. It’s been named “The Black Death” and first occurred in the Mediterranean area around A.D. 542. It went on to become an epidemic, killing millions of people. Around 1347, the bubonic plague took hold in Europe, where it is estimated that over tens of millions of people died over a 300 year span. Interestingly, the Jewish population had much higher survival rates than gentiles, because Jews practiced better sanitary practices, including more frequent bathing and not using dirty surgical tools when someone did get the plague, but rather using herbal medicines. As the plague wound down, modern science was taking hold in Europe.

Robert Hooke developed a compound microscope around 1665. He used thin slices of cork for observation. Live organisms were not observed under a microscope until Anton van Leeuwenhoek utilized lenses to study microorganisms. He made lenses that gave up to 300x magnification and found what he called “animalcules” in food, the sick, and his mouth. Leeuwenhoek observed various types of bacteria, fungi, and protozoa, but to the detriment of microbiology, he refused to sell his microscopes for use, putting a standstill in the advancement of microbiology. It would take more than a century before anyone saw any new information about microbiology.

Once microscopes became widely available, the world of science took off once again. Scientists found that the use of dyes made microbes more visible. Carolus Linnaeus developed the classification system still used today for living organisms. As science progressed, more theories were developed. Two German scientists, Theodor Schwann and Matthias Schleiden, created the cell theory, which states that cells are the essential pieces of life and carry out all of the basic functions of living organisms. This still holds true today for cellular based organisms.

During the mid-nineteenth century, the germ theory of disease was formulated. This states that germs can invade other organisms and cause illness. People did not believe this when it was formulated. People actually believed in spontaneous generation, meaning that these microbes just magically grew up without any living source. When spontaneous generation was disproved, a French scientist named Louis Pasteur developed pasteurization for wine. By heating the wine to 56C without any oxygen present for 30 minutes, he could kill the undesirable microorganisms. Amongst his many major contributions to science was also the rabies vaccine. He made a vaccine for this deadly disease using spinal cord blood from rabies infected rabbits. A boy who was bitten by a dog with rabies was brought to him in hopes of his vaccine preventing the disease taking hold in his body, and this boy went on to survive and be the first person successfully immunized against rabies. As a side note, this same boy was killed by German soldiers in World War II because he refused to grant them access into Pasteur’s tomb. The Pasteur Institute in Paris is still a huge research center for microbiologists worldwide.

Robert Koch developed “Koch’s postulates”, four postulates that are to associate an organism with a specific type of disease, in the late nineteenth century. The postulates assume that disease is only caused by a singular organism, which we know now is not necessarily fact, but was important in development of understanding infectious diseases.

Thanks to the forefathers of microbiology, the advancement of research and the emergence of new fields of study from microbiology have become important in the world of medicine. Immunology, which is the study of the immune system, investigates how a host responds to an invader in the system, which traces back to the study of smallpox by the Chinese. They found that someone who survived smallpox and was scarred by it did not get smallpox again. Thus they took the dried scabs and ground them into a powder that was sniffed and helped prevent a major infection. Edward Jenner was able to develop a prevention to smallpox by using fluid from cowpox on milkmaids. Milkmaids with cowpox didn’t fall victim to smallpox. He inoculated an 8 year old with the cowpox fluid and then inoculated that child with smallpox, only to find the child remained healthy. This gave rise to the name vaccine, derived from Vaccinia, the virus that causes cowpox.

Microbiology also gave rise to virology, the study of viruses; chemotherapy, which was first investigated in the late 19th century, genetics, and molecular biology. What microbiology brought forward was a new breaking ground for scientific research. Thanks to the “Golden Age” of microbiology (1874-1917) many of the diseases that were previously unknown and untreatable now have medicines and vaccines available. Exciting times still lie ahead in the world of microbiology, and the studies of this field will only grow in the next 50 years.