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David Gruby

Born  1810
Died  1898

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Hungarian physician in France, born August 20, 1810, Kis-Kér, Hungary (now Backo Dobro Polje in Serbia-Montenegro); died November 14, 1898, Paris.

Biography of David Gruby

David Gruby is considered the founder of medical microbiology. He was the son of a poor Jewish peasant in a village at Baczka, a fertile district of southern Hungary. He received his first instruction in secular knowledge from a medical student who worked as a substitute teacher in Kis-Kér and lodged in Gruby’s father’s home. In 1824 or 1825 he left Kis-Kér to seek further education in Pest.

His early years had been marked by great poverty, hardship, and prejudice. However, his great talent and determined pursuit of his aim enabled him to succeed in completing his secondary studies at the Piarist Gymnasium in Pest. In 1828 Gruby, then in the fifth year of his studies, went to Vienna to study medicine. He was a hard-working student and particularly concerned himself with anatomy under Christian Joseph Berres (1796-1844), professor of gross macroscopic anatomy. He graduated on August 5, 1839.

As a Jew Gruby had difficulties in finding an education position in surgery following his graduation. He succeeded, however, because of support from Joseph Freiherr von Wattmann-Maelcamp-Beaulieu (1789-1866), a famous surgeon. Gruby then turned to microscopy, which at the time was no science of repute in Wien. He is reported to have built himself an accurate clock and a microscope which was, for the time, an excellent instrument.

Some of Gruby’s early microscopic observations on pathological morphology were included in his dissertation, which contains microscopic observations (with 103 illustrations) on the pathology of body fluids - mucus, sputum, pus, pseudomembranes, coagula, and saliva - and compares pathological with normal findings. His attempt at microscopic differentiation of pus from other pathological substances was a careful, original investigation in a new field of medicine. Gruby demonstrated, among other things, that every one of the studied body fluids contained living elements (leukocytes). He republished his dissertation as the first part of a larger treatise on microscopic pathology, but the other planned parts never appeared.

Gruby also made preparations to be sold to various institutions and gave courses in microscopy, which enabled him to meet many visiting foreign physicians, such as William Bowman (1816-1892) and Philibert Joseph Roux (1780-1854).

After completing his training he was unable to find a suitable position in Wien because he refused to give up his religion. It was Roux who suggested to Gruby that he move to Paris, the great centre of medical learning. Microscopy was little practiced there, and thus Paris offered a promising field for en experienced young man.

Assisted by friends, he obtained a position in the Founding Hospital under the distinguished paediatrician Jacques François Baron (1782-1849) and, urged by some foreign students, he began to give courses in microscopic anatomy and pathology which were attended by Claude Bernard (1813-1878), François Magendie (1783-1855), Henri Milne-Edwards (1800-1885), Marie Jean Pierre Flourens (1794-1867), and many other foreign scientists.

At this time Gruby began to announce his discoveries of various microscopic fungi that produce skin diseases. In 1841 he demonstrated for the first time that a fungus infection of the scalp, called favus, was caused by a fungus. The disease is characterized by thick yellow crusts resembling honeycombs over the hair follicles and accompanied by intense itching. At a time before the use of agar media, Gruby isolated the fungus causing favus, from infected individuals, grew the fungus on slices of potatoes and was able to reproduce the favus disease by carrying out inoculation experiments on healthy tissue. This experiment demonstrated, for the first time, that a micro organism was the cause of a human disease. However, Gruby's research in this area has mostly been ignored, possibly due to strong anti-Semitic feelings, in medicine, at that time.

The following year he described Trichophyton ectothrix, a microscopic cryptogam, found at the roots of a man’s beard, which caused the disease Sycosis barbae. Shortly afterward he discovered Oidium albicans (Monilia albicans), the cause of thrush in infants. In 1843 Gruby described another fungus, which he called Microsporum audouini, in honor of Jean Victor Audouin (1797-1842). In man Microsporum causes a form of tinea (ringworm) that is also called microsporia or Gruby’s disease.

The idea of a plant parasite as a cause of disease in man was something quite new in the era before Louis Pasteur (1822-1895); and Gruby was responsible for the firm establishment of this conception by his findings and experiments, against the doubts, opposition, and ridicule of many contemporary physicians.

In 1843 Gruby discovered an animal parasite in the blood of the frog that he called Trypanosoma because the motion of the mobile organism reminded him of the action of a corkscrew.

In 1847-1848, in the early period of general anaesthesia administered by inhalation, Gruby made experiments on animals with ether and chloroform, which contributed to the knowledge of their effects on several bodily functions. He also emphasized the higher toxicity and quicker action of chloroform as compared with ether.

Gruby was one of the most popular practicians in Paris, famous for the extravagant cures prescribed for his distinguished patients. Among them were Frédéric Chopin, Alexandre Dumas père, Heinrich Heine, Alphonse Lamartine, Alphonse Daudet, George Sand, Ambroise Thomas, and Franz Liszt. These prescriptions were actually clever applications of psychosomatic medicine.

It was only slowly realized that in the short period of his scientific activity Gruby had made very original and important contributions to science - indeed, he founded an important branch of modern medicine, discovering the dermatomycoses, a group of skin diseases caused by parasitic lower plants.

    "Je propose de nommer cet hématozoaire Trypanosome"
    Recherches et observations sur une nouvelle espèce d'hématozoaire,
    Trypanosoma sanguinis.

    Comptes rendus hebdomadaire des séances de l'Académie des Sciences,
    Paris, 1843, 17: 1134-1136, p. 1135

    We thank Patrick Jucker-Kupper, Switzerland, for information submitted.


  • Observationes microscopicae, ad morphologiam pathologicam.
    Vienna, 1839.
  • Observationes microscopicae, ad morphologiam pathologicam. Morphologia fluidorum pathologicorum, tomi primi, pars prima.
    2nd edition of above, Vienna, 1840.
  • Mémoire sur une vegétation qui constitue la vraie teigne.
    Comptes rendus hebdomadaire des séances de l'Académie des Sciences, Paris, 1841. 13: 72-75.
    Independently of Schönlein (Zur Pathogenie der Impetigenes) Gruby discovered the achorion of favus, describing it defintely as the cause of the disease, a point at which Schönlein was in doubt.
  • Recherches anatomiques sun une plante cryptogame qui constitue le vrai muguet des enfants.
    Comptes rendus hebdomadaire des séances de l'Académie des Sciences, Paris, 1842, 14: 634-636.
    Independently of the Swedish paediatrician Fredrik Theodor Berg (1806-1898), Gruby found candida albicans in thrush. He demonstrated its fungal nature.
  • Sur une espèce de mentagre contagieuse résultant du développement d'un nouveau cryptogame dans la racine des poils de la barbe de l'homme.
    Comptes rendus hebdomadaire des séances de l'Académie des Sciences, Paris, 1842, 15: 512-515.
    First accurate description of Trichophyton mentagrophytes, the fungus responsible for sycosis barbae. English translation of this and Gruby's other five papers read to l'Académie des Sciences in Zakon & Benedek, David Gruby and the centenary of medical mycology, 1841-1941, Bulletin of the History of Medicine, 1944, 16: 155-168.
  • Recherches sur la nature, le siège et le développement du Porrigo decalvans ou phytoalopécie.
    Comptes rendus hebdomadaire des séances de l'Académie des Sciences, Paris, 1843, 17: 301-303.
    First accurate description of Microsporon audouini, the fungus of Willan's porrigo decalvans, tinea tonsurans, Gruby's disease.
  • Recherches et observations sur une nouvelle espèce d'hématozoaire, Trypanosoma sanguinis.
    Comptes rendus hebdomadaire des séances de l'Académie des Sciences, Paris, 1843, 17: 1134-1136.
  • Recherches sur les cryptogames qui constituent la maladie contagieuse du cuir chevelu sous le nom de Teigne (Mahon). Herpes tonsurans (Cazenave).
    Comptes rendus hebdomadaire des séances de l'Académie des Sciences, Paris, 1844, 18: 583-585.
    Gruby discovered a fungus, Trichophyton tonsurans, in ringworm of the scalp. Biographical:
  • B. B. Beeson:
    David Gruby, M.D. (1810-1898).
    Archives of Dermatology and Syphilology, Chicago, 1931, 23: 141-144.
  • Vladislav Kruta (1908-1979):
    Gruby, David. In: Charles Coulston Gillispie, editor in chief: Dictionary of Scientific Biographies. Charles Scribner’s Sons. New York, 1970. Pages 565-566.
  • T. Kovac:
    [On the 185th anniversary of the birth of David Gruby (1810-1898)] [Article in Croatian]
    Medicinski Pregled, Novi Sad, Serbia, 1995, 48 (3-4): 123-128.
  • E. Podolsky:
    David Gruby and the fungus growths.
    The Medical Annals of the District of Columbia, Washington, DC, January 1957, 26 (1): 24-26.

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