Heinrich Hermann Robert Koch, who was to make his name as Robert Koch in the field of microbiology, was one of thirteen children in the family of a mining engineer. He was born on December 11 1843 in Clausthal, which is in the Upper Harz Mountains of Germany. An extremely intelligent boy, he surprised his parents when at the age of five he taught himself to read with the aid of newspapers. He attended the local "Gymnasium" or high school where he showed an enthusiastic interest in biology.
He went on to study medicine at the University of Gottingen. Among his professors at university was Friedrich Henle who made important innovations in histology as well as publishing a paper supporting theory that living organisms caused infectious diseases. Another professor was the chemist Friedrich Wohler who was the first person to synthesize urea. Koch obtained his MD in 1866.
In 1866, he married Emmy Fraats and they had one child, a daughter called Gertrud.
Having graduated he went to study chemistry in Berlin for six months. Then after a short time as an assistant at the Hamburg General Hospital, he started working in general practice. His first practice was in Langenhagen before he moved to Rackwitz in the Province of Posen in 1869. While at Rackwitz, he passed the District Medical Officers examination. In 1870, he volunteered to serve with the army as a surgeon in the Franco-Prussian War.
After the war, in 1872, Koch returned to civilian life becoming the District Medical Officer for Wollstein in the Prussian area of Poland. In Wollstein, he started the careful scientific investigations into microbial diseases that were to make his name.
The first disease he worked on was Anthrax, which afflicted many farm animals in the Wollstein area. Casimir-Joseph Davaine first described the Anthrax bacillus in 1863. How it caused the illness and in particular how it remained viable in the environment was a mystery at the time. He used part of his four roomed home as a laboratory and with a microscope bought for him by his wife carried out very detailed and painstaking investigations. He confirmed that blood from an infected animal could infect another animal.
By growing the bacterium in the sterile aqueous humor of ox's eyes, he showed that the organism was still infectious after several generations of growth outside of a living animal. He also observed the formation of endospores in the bacilli particularly when they were subject to adverse conditions. Koch correctly deduced that these spores allowed Anthrax to persist in the environment. This allowed the infection to remain dormant in a field even when no animals grazed in that field for a number of years. He presented his results at the University of Breslau and the University published his paper on the subject in 1876.
He then turned his mind to investigating the organisms commonly found in infected wounds. At the same time as carrying out this study, which he published in 1878, he improved his methods for staining and growing bacteria as well as photographing them. All this painstaking work he carried out in his own home based laboratory.
In 1879, he moved to Breslau as District Medical Officer before going to Berlin the following year to take up the appointment of a post with the Imperial Health Offices. This post dealt with giving advice on hygiene and public health. With this new post, he also had access to laboratory facilities in Berlin and he continued his research on pathogenic microorganisms.
He started to develop means of growing organisms on solid media. At first, he used potatoes and or media containing gelatin. Eventually he made media with the gelling agent agar-agar prepared in the newly developed Petri dishes. Julius Richard Petri, who was one of his assistants in Berlin, invented these dishes. Agar based culture media in Petri dishes is still in use in microbiology laboratories today.
In 1881, as part of the advice remit of his job, he suggested the heat sterilization of all surgical instruments prior to use. There is no telling how many peoples lives he saved by issuing this simple instruction.
During the nineteenth century, the infectious disease tuberculosis caused one in seven deaths and Robert Koch put his keen mind into finding the causative organism on this illness. On March 24 1882, he announced the identification of the bacillus Mycobacterium tuberculosis. He went on to produce an extract from the bacterium called tuberculin, which he hoped, would act as a vaccine or even a cure for tuberculosis. While tuberculin has proved very useful in identifying exposure to the disease Koch's hopes for a cure or vaccine were not realized. Later work carried out by him led him to believe that two different species of Mycobacterium caused human and bovine tuberculosis. This went against the ideas of many other scientists at the time but has now been shown to be correct.
Also in 1882, he formalized his postulates on infectious diseases. The Koch's postulates, as they are known, are taught to students studying medical microbiology today. Koch's postulates state:
* That the organism should be isolated in every instance of the disease;
* That, extracted from the body, the germ can be grown in a pure culture and maintained over several microbial generations.
* That the disease should be reproducible in an experimental animal when inoculated with a pure culture removed by numerous generations from the organisms initially isolated;
* That the organism should be isolated from the inoculated animal and cultured anew.
Koch hoped that once an organism was found that conformed to these postulates then methods of fighting the disease it caused could be found.
In 1885, the government sent Koch to Egypt to study an outbreak of cholera. At the time he arrived, the outbreak was ending but he was able to isolate a comma shape organism from some cases. While in Egypt, he did find the cause of amoebic dysentery and the bacteria, which caused two types of conjunctivitis. At a later outbreak in India, he was able to confirm the comma shaped bacterium as the cause of cholera. The comma shaped organism now known as Vibrio cholerae. Returning to Berlin, he recommended regular checks on the domestic water supply as well as improvements to sewage disposal to prevent any future outbreak of cholera.
Koch also investigated bubonic plague where he found rats acting as vectors for the illness. He found the tsetse fly was responsible for the transmission of sleeping sickness. He did investigate malaria and while he suspected the mosquito was responsible for its transmission, he was not able to prove this theory. Other infectious illnesses he studied over the years include leprosy, rinderpest and Texas cattle fever. To study such diseases he knew he would have to travel. In addition to Egypt and India over the years, he went to South Africa, Central Africa and Java to study infections.
In Germany, the University of Berlin appointed Koch to the post of professor of hygiene in 1885. In 1891, he left this post to become the director of the newly formed Prussian Institute for Infectious Diseases. This institute was later renamed The Robert Koch Institute.
In 1905, the Noble Prize committee awarded Robert Koch the Nobel Prize for Physiology or Medicine "For his investigation and discoveries in relation to tuberculosis".
Koch returned to Central Africa in 1906 to work on the control of human trypanosomiasis. He reported that the drug atoxyl was effective in treating this disease.
He continued his work in microbiology until his death in 1910 of a heart attack. He died in the town of Baden-Baden in Germany.
While now most microbiologists will specialize in one field of microbiology Koch looked into many aspects of the science. He worked with human bacterial infections such as cholera. Some infections were primarily animal infections but could impact on humans like anthrax. Rinderpest and Surra are purely animal pathogens and are part of veterinary medicine. He also worked with parasitical diseases such as malaria and trypanosomiasis.
Along with Louis Pasteur, Robert Koch has been called the founder of medical microbiology. Many of the techniques he developed over a hundred years ago are still in use in bacteriology laboratories around the world. This, if nothing else, justifies the accolade.