Robert Koach

 

 

 

Robert Koch was born on December 11, 1843, at Clausthal in the Upper Harz Mountains. The son of a mining engineer, he astounded his parents at the age of five by telling them that he had, with the aid of the newspapers, taught himself to read, a feat which foreshadowed the intelligence and methodical persistence which were to be so characteristic of him in later life.

In 1862 Koch went to the University of Göttingen to study medicine. Here the Professor of Anatomy was Jacob Henle and Koch was, no doubt, influenced by Henle's view, published in 1840, that infectious diseases were caused by living, parasitic organisms. After taking his M.D. degree in 1866, Koch went to Berlin for six months of chemical study and there came under the influence of Virchow. In 1867 he settled, after a period as Assistant in the General Hospital at Hamburg, in general practice, first at Langenhagen and soon after, in 1869, at Rackwitz, in the Province of Posen. Here he passed his District Medical Officer's Examination. In 1870 he volunteered for service in the Franco-Prussian war and from 1872 to 1880 he was District Medical Officer for Wollstein. It was here that he carried out the epoch-making researches which placed him at one step in the front rank of scientific workers.

Anthrax was, at that time, prevalent among the farm animals in the Wollstein district and Koch, although he had no scientific equipment and was cut off entirely from libraries and contact with other scientific workers, embarked, in spite of the demands made on him by his busy practice, on a study of this disease. His laboratory was the 4-roomed flat that was his home, and his equipment, apart from the microscope given to him by his wife, he provided for himself. Earlier the anthrax bacillus had been discovered by Pollender, Rayer and Davaine, and Koch set himself to prove scientifically that this bacillus is, in fact, the cause of the disease. He inoculated mice, by means of home-made slivers of wood, with anthrax bacilli taken from the spleens of farm animals that had died of anthrax, and found that these mice were all killed by the bacilli, whereas mice inoculated at the same time with blood from the spleens of healthy animals did not suffer from the disease. This confirmed the work of others who had shown that the disease can be transmitted by means of the blood of animals suffering from anthrax.

But this did not satisfy Koch. He also wanted to know whether anthrax bacilli that had never been in contact with any kind of animal could cause the disease. To solve this problem he obtained pure cultures of the bacilli by growing them on the aqueous humour of the ox's eye. By studying, drawing and photographing these cultures, Koch recorded the multiplication of the bacilli and noted that, when conditions are unfavourable to them, they produce inside themselves rounded spores which can resist adverse conditions, especially lack of oxygen and that, when suitable conditions of life are restored, the spores give rise to bacilli again. Koch grew the bacilli for several generations in these pure cultures and showed that, although they had had no contact with any kind of animal, they could still cause anthrax.

 

11 December 1843 – 27 May 1910 was a celebrated German physician and pioneering microbiologist. The founder of modern bacteriology, he is known for his role in identifying the specific causative agents of tuberculosis, cholera, and anthrax and for giving experimental support for the concept of infectious disease.

 In addition to his trail-blazing studies on these diseases, Koch created and improved laboratory technologies and techniques in the field of microbiology, and made key discoveries in public health

 His research led to the creation of Koch’s postulates, a series of four generalized principles linking specific microorganisms to specific diseases that remain today the “gold standard” in medical microbiology. As a result of his groundbreaking research on tuberculosis, Koch received the Nobel Prize in Physiology or Medicine in 1905.

The German doctor Robert Koch is considered the founder of modern bacteriology. His discoveries made a significant contribution to the development of the first ‘magic bullets’ - chemicals developed to attack specific bacteria - and Koch was awarded a Nobel Prize in 1905.

Koch developed a new experimental method to test whether a particular micro-organism is the cause of a disease. Building on Pasteur's work on germ theory, Koch used experiments to prove that the bacterium Bacillus anthracis was the cause of anthrax - the bacterium could be observed in the tissue of anthrax victims. He extracted this bacterium from a sheep which had died of anthrax, grew it and injected a mouse with it. The mouse developed the disease as well. Koch repeated this process over 20 generations of mice, before he announced in 1876 that he had proved this bacterium caused anthrax.

Koch continued to improve his methods and techniques. By solidifying liquids such as broth with gelatine and agar, for instance, he created a solid medium for growing bacteria which was easier to handle than the liquids used by Pasteur. Koch's assistant Julius Richard Petri (1852-1921) developed the Petri dish, which made the observation of bacteria even easier.

Koch and his team also developed ways of staining bacteria to improve the bacteria’s visibility under the microscope, and were able to identify the bacterial causes of tuberculosis (1882) and cholera (1883). Adopting Koch's method, other researchers were able to identify the bacteria that caused diseases such as typhus (1880), tetanus (1884) and the plague (1894).

Koch was the recipient of many prizes and medals, honorary doctorates of the Universities of Heidelberg and Bologna, honorary citizenships of Berlin, Wollstein and his native Clausthal, and honorary memberships of learned societies and academies in Berlin, Vienna, Posen, Perugia, Naples and New York. He was awarded the German Order of the Crown, the Grand Cross of the German Order of the Red Eagle (the first time this high distinction was awarded a medical man), and Orders from Russia and Turkey. Long after his death, he was posthumously honoured by memorials and in other ways in several countries.

In 1905 he was awarded the Nobel Prize for Physiology or Medicine. In 1906, he returned to Central Africa to work on the control of human trypanosomiasis , and there he reported that atoxyl is as effective against this disease as quinine is against malaria. Thereafter Koch continued his experimental work on bacteriology and serology.

 

Koch’s postulates

For thousands of years, epidemics of contagious diseases were believed to be caused by the wrath of the gods, configuration of stars, or miasma. The association of specific microorganisms with disease came about as a consequence of the work of the German physician Robert Koch. He formulated a set of criteria that could be used to identify the pathogen responsible for a specific disease. These criteria came to be known as Koch’s postulates:

1.      The organism must be regularly associated with the disease and its characteristic lesions.

2. The organism must be isolated from the diseased host and grown in culture.
3. The disease must be reproduced when a pure culture of the organism is introduced into a healthy, susceptible host.
4. The same organism must be reisolated from the experimentally infected host.

Koch applied these criteria to show that anthrax, a common disease of cattle, was caused by the bacterium Bacillus anthracis , and that tuberculosis in humans was caused by a different bacterial species. His postulates provided a framework for proving the role of microbes in disease. As a consequence of his work, the study of infectious disease was placed on a secure scientific foundation, which ultimately made possible rational treatment and control.