Anthrax was discovered
Robert Koch was born on December 11, 1843, in the city of Clausthal in the modern German state of Lower Saxony. After graduating from the University of Göttingen, he worked as a doctor for several years and even volunteered for the Franco-Prussian War of 1870-1871 in an attempt to rescue the wounded. After his discharge, he was about to continue his medical career, but his wife gave him a microscope and Koch set up a special microbiology laboratory.
His first major success was the isolation of a pure culture of anthrax bacilli (Bacillus anthracis) in 1877. This bacteria is common in cattle but can also cause anthrax in humans. It was obtained from the blood of infected animals and propagated in the eye fluid of cows. Koch tried an innovative method: growing a culture in a drop of liquid suspended on the bottom surface of a coverslip (top) glass and looking at it through a microscope. This technique became the standard in microbiology for many years.
He took a photo of the bacteria and identified its spores by color. Spores can remain dormant for long periods of time, but under favorable conditions they “come to life”, making the bacterial culture more viable. Thus, anthrax can be transmitted to new, healthy animals even if there are no longer any infected animals: it is enough for drops of dried blood or other biological traces to remain on the farm.
Koch managed to prove this exactly Bacillus anthracis Although biologists at the time did not believe that many diseases had a specific causative organism, anthrax was the cause.
This is believed to be the first evidence of a direct link between a pathogen and a disease in the history of biology.
The success was overwhelming, and leading German scientists paid attention to the microbiologist. He was soon invited to work as a consultant at the Reichs Public Health Agency in Berlin.
Tuberculosis and guinea pigs
Anthrax is very harmful to farmers but rarely causes serious outbreaks in humans. A much more serious threat in the 19th century was tuberculosis, which affected the lungs, causing hemoptysis and severe weakness. It was almost impossible to get rid of the disease with “folk” methods (it is also difficult to use scientific medical methods). The dominant theory in the early 1880s was that tuberculosis was a complex hereditary disease, but Koch was confident that tuberculosis had a causative agent.
In 1881, the scientist began a series of experiments to find the desired bacterium. First, he transplanted tuberculosis tissue into guinea pigs. When they got sick, the hypothesis could be considered proven, but Koch needed a pathogen that couldn’t be found.
As it turned out later, bacteria Tuberculosis It is covered with a waxy substance and therefore takes dye very poorly. To detect them, two dyes (blue and light brown) had to be added at the same time.
“When the coverslips were exposed to this staining liquid (methylene blue mixed with potassium hydroxide) for 24 hours, very small rod-shaped forms began to appear for the first time in the tubercle mass, which, as subsequent observations showed, multiplied and formed spores and was therefore the same organism as the anthrax bacillus.” belongs to the group. Microscopic examination then showed that only the previously blue-coloured cell nuclei and debris had turned brown, while the tuberculosis bacilli remained a beautiful blue colour.” aforementioned Koch at the conference of the German Physiological Society in Berlin, 24 March 1882.
Not all scientists accepted this theory, and the discovery of Koch bacillus spores turned out to be false. Despite this, for the discovery, Kaiser Wilhelm I awarded the scientist the rank of Privy Councilor of the Government.
tuberculin scandal
Koch made many more discoveries and became known as one of the most prominent microbiologists of the period, but his career was overshadowed by a serious scandal. Tuberculosis is highly resistant to treatment, but since the discovery of the bacterium there have been hopes of finding a vaccine or drug. Koch also pioneered the search for a cure. By 1888, he drew attention to the antibacterial properties of some synthetic dyes and conducted hundreds of experiments with them, but all were in vain.
To his misfortune, he discovered that an extract of a culture of tuberculosis bacteria dissolved in glycerin claimed to be able to cure tuberculosis in guinea pigs.
“I have identified a substance whose action renders laboratory animals insensitive to tuberculosis bacillus vaccine. It stops the tuberculosis process in already infected animals. I can say with certainty that guinea pigs are quite susceptible to disease. [туберкулезу]no longer responds to virus vaccine [бактерией] When treated with this substance, tuberculosis disease occurs,” he said at the International Medical Congress in Berlin.
Many people believed the great scientist and specially came to Berlin to buy the miraculous medicine. Koch’s 17-year-old girlfriend also received this award. Before the appointment, the biologist assured him that he would “probably survive.” At that time, there were no standards for testing drugs and vaccines. No one other than Koch had ever seen the same guinea pigs purportedly cured with this extract.
Later experiments showed that after the substance was administered to sick pigs, they developed severe symptoms, and in humans the reaction was even worse. They started to have fever and pain in their joints. The chemical structure of the drug was also unclear; Koch kept this secret by presenting the drug as tuberculin.
Worse. Pathologist Rudolf Virchow proved that the drug not only destroys Koch’s bacillus, but also activates “sleeping” organisms. Tuberculin turned out to be a counterfeit drug: today it is called an “unproven drug”, simply “fuflomycin”.
The drug was taken by 1061 patients with internal organ tuberculosis and 708 patients with external tissue tuberculosis. The “treatment” of at least 21 of them resulted in death. To escape the scandal, Koch took a long vacation and fled to Egypt. The incident led to the development of standards for testing drugs before they enter the market.
Koch’s reputation was damaged, but despite this, his services to science were great. In 1905, he received the Nobel Prize in Physiology or Medicine for his “research and discoveries concerning the treatment of tuberculosis.” Tuberculin was not in vain: since it caused severe symptoms in tuberculosis patients, it began to be used to detect latent infection in humans. A similar substance is used today for the Mantoux reaction.