Antonie van Leeuwenhoek was a Dutch scientist. He is commonly known as "the Father of Microbiology", and considered to be the first microbiologist. He is best known for his work on the improvement of the microscope and for his contributions towards the establishment of microbiology.
He spent his time grinding increasingly tiny lenses to use in microscopes and he made about 200 microscopes with different magnifications.
Francesco Redi was an Italian physician and poet. At the time when he was alive, it was a common belief that maggots arose spontaneously in rotting meat. But Redi believed that maggots developed from eggs laid by flies. He set out meat in a variety of flasks and as he expected, maggots appeared only in the open flasks in which the flies could reach the meat and lay their eggs. Even though he found this out, the belief in spontaneous generation remained strong and no-one believed him.
Edward Jenner was an English physician and scientist who was the pioneer of smallpox vaccine, the world's first vaccine. He is often called "the father of immunology", and his work is said to have "saved more lives than the work of any other human" because of his vaccines.
John Snow was an English physician and a leader in the adoption of anaesthesia and medical hygiene. He is considered one of the fathers of modern epidemiology, because of his work in tracing the source of a cholera outbreak in Soho, London, in 1854.
Ignaz Semmelweis was a Hungarian physician of German extraction now known as an early pioneer of antiseptic procedures. Described as the "savior of mothers", Semmelweis discovered that the incidence of puerperal fever could be drastically cut by the use of hand disinfection in obstetrical clinics. Puerperal fever was common in mid-19th-century hospitals and often fatal so this discovery was a breakthrough.
Joseph Lister was a British surgeon and a pioneer of antiseptic surgery. By applying Louis Pasteur's advances in microbiology, he promoted the idea of sterile surgery while working at the Glasgow Royal Infirmary. Lister successfully introduced carbolic acid (now known as phenol) to sterilise surgical instruments and to clean wounds, which led to a reduction in post-operative infections and made surgery safer for patients.
Robert Koch demonstrated that the disease anthrax was caused by a bacterium. His basic criteria that proved the germ theory are now called Koch’s postulates and are still used today as a check list for proving that an infectious organism actually causes a specific disease:
1. The microorganism must be observed in every case of the disease.
2. The microorganism must be isolated and grown in pure culture.
3. The pure culture, when inoculated (injected) in a healthy animal, must produce the disease.
4. The same microorganism must then be recovered from the diseased animal.
Louis Pasteur was a French chemist and microbiologist renowned for his discoveries of the principles of vaccination, microbial fermentation and pasteurisation. Pasteur's hypothesis was that if cells could arise from nonliving substances, then they should appear spontaneously in sterile broth. Pasteur showed that microorganisms grew in broth in a sealed tube, but no growth or spoiling of the broth occurred if it was boiled first. Boiling killed the bacteria and other microorganisms.
Alexander Fleming was a Scottish biologist, pharmacologist and botanist. He wrote many articles on bacteriology, immunology, and chemotherapy. His best-known discoveries are the enzyme lysozyme in 1923 and the antibiotic substance penicillin from the mould Penicillium notatum in 1928, for which he shared the Nobel Prize in Physiology or Medicine in 1945.