Casimir Davaine

Casimir Davaine

Casimir-Joseph Davaine (born March 19, 1812 in Saint-Amand-les-Eaux , France , † October 14, 1882 in Garches / Département Seine-et-Oise near Paris ) was a French doctor , pathologist and parasitologist . Using the example of anthrax, he was the first to show that bacteria can cause disease in humans and animals. As part of these experiments, he transferred blood from diseased sheep to smaller animal species, such as rabbits, rats or guinea pigs, with which he established animal experiments under laboratory conditions.

Life

Casimir Davaine was the sixth of nine children of a brandy distiller. He went to school in Saint-Amand, Tournai and Lille and began studying medicine in Paris in 1830. In 1835 he became "external" (medical assistant who does not live in the hospital) of Pierre Rayer (1793-1867) at the Hôpital de la Charité , where he also met the famous physiologist Claude Bernard , whose colleague, friend and family doctor he became. In 1837 he completed his medical studies, received his doctorate with De l'hématocèle de la tunique vaginale and established himself as a practicing doctor. He devoted his free time to research in natural history and pathology.

In 1848 he and Rayer were among the founding members of the Société de Biologie . In 1858 he was awarded the Cross of the Legion of Honor, in 1868 he was given a seat in the Academy of Medicine . He bore the title of médecin par quartier of the French emperor, so he was called in for consultations about the state of health of the emperor without serving him exclusively as a personal physician. Davaine was one of the most famous doctors of his time. His patients included Marie Duplessis , who became known as the "Lady of the Camellias", Claude Bernard, his teacher Rayer and members of the Rothschild and d'Eichthal families.

In the Franco-Prussian War of 1870/71 he served as a field doctor. During this time he wrote the booklet Les éléments du bonheur ("Elements of Happiness"), in which he expanded his philosophy of life. He spent his last years in Garches near Paris, where he grew roses after the war.

plant

Davaine's work included papers in bacteriology , parasitology , plant physiology , zoology , general biology and teratology . However, his work on anthrax, with which he founded medical and veterinary bacteriology, was particularly epochal.

anthrax

When Davaine began working on anthrax , the disease was known to be contagious and virulent. As early as 1823, Eloy Barthélemy had shown at the Alfort Veterinary School that he could transmit anthrax to a healthy sheep with the blood from the spleen of a diseased sheep. Nevertheless, the miasmatic theory of anthrax development was still prevalent, according to which the disease should arise from miasms from the soil, artificial irrigation or other meteorological factors. Other authors blamed poor food, dirty stalls or “too much blood in the arteries”.

Bacillus anthracis , in earlier terminology Bacteridium anthracis

In June and July 1850 Davaine accompanied his former teacher Rayer on a research trip to the Beauce region near Chartres , where they transmitted anthrax with the blood of sick to healthy sheep. Under the microscope, Rayer observed that the red blood cells in the blood of the artificially infected animals clumped together in the same way as in the original animals. He also observed small, thread-like bodies in the blood that were twice as long as a blood cell. This is the first observation of the anthrax pathogen Bacillus anthracis . However, Rayer did not yet associate the "small, thread-like bodies" with the disease.

In 1855 the German doctor Aloys Pollender published a work for which he wanted to have made the observations as early as 1849. He found "rod-shaped bodies" in the blood, which he speculated could belong to the bacteria. In this work he asked whether it was the infectious agent, the carrier of this agent or an irrelevant observation, but said that this question could not be answered. In 1857/58 another German researcher, Friedrich Brauell , also observed the rod-shaped bodies that Rayer and Pollender had already seen. It seemed to him as if the initially motionless rods began to move later, i.e. were vibrions. This confusion of the anthrax pathogen with other bacteria that appear during the decomposition hindered the progress of knowledge for a long time.

Davaine resumed his anthrax research in 1863. He infected two rabbits and a white rat with the blood of a sheep that had died of anthrax. He was able to show that the blood of animals with anthrax was not infectious as long as the rod-shaped bodies had not appeared. He suggested the name bactéridies for these corpuscles . He was also able to demonstrate that putrid anthrax blood caused a disease other than anthrax when transmitted, so Davaine distinguished septicemia from anthrax. Dried blood from anthrax animals remained virulent eleven months after drying it when re-moistened and transferred. Birds and frogs proved to be insensitive to anthrax in his experiments. He also showed that not only the blood of the spleen - as had been believed until then - but blood of all kinds was infectious.

Anthrax infection on the forearm

In 1864 Davaine examined anthrax carbuncle ( pustula maligna ), that is, the localized form of skin anthrax , in humans and found the same bacteria under the microscope that he had seen in the blood of sick animals. He thus confirmed the results of Jean Fournier, who had shown as early as 1789 that anthrax can be transmitted from animals to humans.

Davaine's findings were heavily attacked by Émile-Claude Leplat and Pierre-François Jaillard of the Val-de-Grace Hospital . They couldn't imagine that bacteria could cause disease. In the eyes of Leplat and Jaillard, the rod-shaped corpuscles were insignificant side effects. Davaine was finally able to show that in the experiments referred to by Leplat and Jaillard, a completely different disease - bovine septicemia - had been transmitted. In 1865 Davaine was awarded the Prix Bréant by the Academy of Sciences for his anthrax research, but doubts still remained.

In 1868 Davaine tried to dispel these last doubts in a review and affirmed that the "bacteridia" were the causative agents of the disease. Above all, he pointed out that a certain plant disease was also caused by bacteria. In this case, when the bacteria were heated to at least 52 ° C, the bacteria would stop moving, and Davaine could no longer transmit the disease.

That same year, Davaine determined the incubation period for anthrax in guinea pigs. Death occurred between 26 and 53 hours after injection of the blood of anthrax animals, depending on the dose of Davaine transferred. Davaine had shown that the incubation time was dependent on the dose and thus gained an additional argument for the cause of the anthrax through the "bacteridia" he observed.

In 1869 he succeeded in an elegant experiment: he diluted some blood from animals with anthrax with distilled water, whereby after 24 hours the anthrax pathogens had sunk to the bottom of the vessel. If he injected a drop from the bottom of the jar into guinea pigs, they died, but if he took a drop from the surface, they survived.

In 1873 Davaine was able to show that diluted blood of animals with anthrax lost its infectivity when it was heated to 55 ° C for five minutes. However, the blood remained contagious when he dried it, even if it was heated to 100 ° C afterwards. He also examined various chemicals for their bactericidal effect.

However, Davaine continued to err in the transmission of the disease for which he blamed flies. Nor did he succeed in isolating the bacterium and cultivating it in vitro. It was only Robert Koch who described the spore stage of the anthrax pathogen and thus completed the life cycle of the bacterium. Louis Pasteur recognized on several occasions the pacemaker Casimir Davaine had played for him.

literature

• Werner Köhler : Davaine, Casimir-Joseph. In: Werner E. Gerabek , Bernhard D. Haage, Gundolf Keil , Wolfgang Wegner (eds.): Enzyklopädie Medizingeschichte. De Gruyter, Berlin / New York 2005, ISBN 3-11-015714-4 , p. 289.

Individual evidence

1. ↑ ^{a b} Rayer: Inoculation du sang de rate . In: Comptes rendus des séances et mémoires de la Société de Biologie . Vol. 2, 1850, pp. 141-144.
2. ^ C. Davaine: Recherches sur les infusoires du sang dans la maladie connue sous le nom de sang de rate . In: Comptes rendus de l'Académie des Sciences . Vol. 57, 1863, pp. 220, 351 and 386.
3. ↑ C. Davaine: Sur la nature des maladies charbonneuses . In: Archives générales de Médecine . Vol. 11, 1868, pp. 144-148.
4. ^ C. Davaine: Experiences relatives à la duration de l'incubation des maladies charbonneuses et à la quantité de virus nécessaire à la transmission de la maladie . In: Bulletin de l'Académie impériale de Médecine . Vol. 33, 1868, pp. 816-821.

Web links

• Casimir Joseph Davaine: De l'hématocèle de la tunique vaginale . Thèse de médecine de Paris n ° 428, 1837. ( Doctoral thesis by Davaine )
• Jean Théodoridès: Casimir Davaine (1812-1882): A Precursor of Pasteur . In: Medical History . Vol. 10, No. 2, 1966, pp. 155-165. PMC 1033586 (free full text)