(b. Galati, Romania, 19 July 1874; d. Paris, France, 5 September 1953),
Orphaned at the age of eight, Levaditi was raised by an aunt in the port city of Galati. This stimulating environment heightened the sense of independence and initiative that he owed to his naturally lively intelligence. This aunt later entrusted him to his other aunt, a laundress at the Branconvan Hospital in Bucharest, where he completed his secondary schooling and medical studies. In 1895 he was accepted into the laboratory of Victor Babès. There he found his lifework: scientific research, particularly on the actinomycotic form of the tubercle bacillus. In 1898 Levaditi worked in Paris with Charles Bouchard and also with Albert Charrin at the Collège de France. Then, at Frankfurt am Main, he studied with Paul Ehrlich, whose views on chemotherapy profoundly influenced him. Admitted in 1900 to the Pasteur Institute, he served as assistant to Élie Metchnikoff in his work on phagocytosis and syphilis. Soon, however, he began to devote himself to his own research.
Levaditi received the M.D. at Paris in 1902. He became head of the laboratory of the Pasteur Institute in 1910 and in 1926 its chef de serυice. Throughout this period he trained numerous students and disciples. Entering World War I as a volunteer, he attained the rank of captain and was detached to serve with the ambulances of la Panne. In this capacity he worked on developing an antitetanus vaccine and studied streptococcus in wounds. After the war he resumed his work at the Pasteur Institute, adding new projects to those already in progress. After 1932 Levaditi divided his time between the Pasteur Institute and the Alfred Fournier Institute, which was the center for the French National League Against Venereal Diseases. After retiring from the Pasteur Institute in 1940, he devoted his efforts to the latter organization until his death at the age of seventy-nine.
In 1903 Levaditi married a Romanian woman who bore him two children. His son, Jean C. Levaditi, became head of the department of histopathology at the Pasteur Institute.
Levaditi became a naturalized French citizen in 1907. He was a member of many French and foreign academies, including the Académie de Medécine, to which he was named in 1928. He was commander of the Legion of Honor and received many prizes, including Cameron Prize (Edinburgh) in 1928, the Paul Ehrlich Prize in 1931, and eight prizes from the Académie des Sciences of Paris.
Levaditi published more than 1,200 notes, articles, and monographs. His penetrating intuition, enhanced by his power of reasoning and remarkable technical knowledge, enabled him to stay informed about new developments; by isolating these developments from their original context in order to set them against his own conceptions, he produced an immense body of work. Thus he noticed that the origin of a group of viral diseases whose agent he named ultravirus was still unknown. This group provided the connecting link for all his investigations, which were outwardly dissimilar (for instance, neurotropic skin diseases).
Levaditi dominated the study of syphilis in his time. After the discovery of the Treponema pallidum by Fritz Schaudinn and Paul-Erich Hoffmann, he studied it, using the silver-salt staining method, in the livers of newborn congenital syphilitics. He demonstrated that to supplement the Wassermann-Bordet reaction, a normal liver could be used for diagnosis, thus pioneering the study of antigens. Following Benjamin Sauton, he, Robert Sazerac, and Louis Fournier applied bismuth therapy to syphilis, and achieved results with metallotherapy. He was put in charge of Wassermann serum diagnosis at the Pasteur Institute. Levaditi also used stovarsol (Fourneau 190) in syphilis therapy, after its discovery by Fourneau, Jacques and Thérèse Tréfouël, and Navarro-Martin.
Inspired by Pasteur’s work on rabies, Levaditi carried out important experiments on lethargic encephalitis. With Karl Landsteiner he established that the poliomyelitis virus is an ultravirus. During the epidemics in Sweden in 1913 and in Alsace in 1930 he was in charge of committees of assistance. In 1930 Louis Pasteur Vallery-Radot wrote that in France, Levaditi was “the instigator of all research on the etiology of poliomyelitis.”
From 1936 to 1940 Levaditi studied the sulfamides and their derivatives. Beginning in 1946 he turned to antibiotics and their mechanisms, which he examined through experimentation on animals. He wrote several important monographs soon after the discovery of each new antibiotic. Levaditi continued his studies of viruses and of chemotherapeutic action on bacteria until his death. A major result of this dedicated effort was his discovery of what are today called the interference phenomena.
I. Original Works. Bibliographies of monographs and articles by Levaditi are his Traυaux de médecine expérimentale, 1897-1931. Ectodermoses neurotropes, neuroprotozooses, syphilis, chimiothérapie et chimioprévention, phagocytose, immunité, érythème polymorphe, rhumatisme, ergostérol irradié (Paris, 1931); and Titres et travaux. Microbiologie, pathologie humaine et animale, chimiothérapie. 1897-1951 (Paris, 1952).
His writings include La leucocytose et ses granulations (Paris, 1902); La nutrition dans ses rapports avec l’immunité (Paris, 1904); La réaction des anticorps syphilitiques dans la paralysie générale et le tabès (Paris, 1906), written with A. Marie; La syphilis (Paris, 1909), written with F. Roché; Traitement de la paralysie générale par injection du sérum savarnisé dans la dure-mère cérébrale (Paris, 1913),written with A. Marie et T. Martel; Étude sur le tréponème de la paralysie générale (Paris, 1919), written with A. Marie; Les ectodermoses neurotropes, poliomyélite, encéphalite, herpès (Paris, 1922), with preface by E. Roux; “Vaccine pure cérébrale, virulence pour l’homme,” in Comptes rendus hebdomadaires des séances de l’Académie des sciences, 174 (1922), 248-252, written with S. Nicolau; Étude de l’action thérapeutique sur la syphilis (Paris, 1923), written with R. Sazérac; Le bismuth dans le traitement de la syphilis (Paris, 1924); L’herpès et le zona (Paris, 1926); Travaux de microbiologie et de pathologie humaines et animales. 1897-1933 (Paris, 1993); Prophylaxie de la syphilis (Paris, 1936); Traité des ultravirus des maladies humaines et animales, 2 vols. (Paris, 1943-1948); La pénicilline et ses applications thérapeutiques (Paris, 1945); Précis de virologie médicale (Paris, 1945); La streptomycine et ses applications thérapeutiques, pricipalement dans la tuberculose (Paris, 1946); Les antibiotiques autres que la pénicilline (Paris, 1950); and Le chloramphénicol et ses applications thérapeutiques (Paris, 1951).
II. Secondary Literature. On Levaditi and his work, see R. Dujarric de La Rivière, Souvenirs (Périgueux ), pp. 136-137; E. Iftimovici, C. Levaditi(Bucharest, 1960); P. Lépine, “Constantin Levaditi (1874-1953),” in Presse médicale, 71 (1953), 1455; and “C. Levaditi, 1874-1953,” in Annales de l’Institut Pasteur, 85 (1953), 355; L. Pasteur Vallery Radot, “La poliomyélite épidémique,” in Revue des deux mondes, 9 (1930), 899-914; E. Roux, “Rapport sur les travaux de M. le Docteur C. Levaditi. Sur les spirochètes en général et le Treponema pallidum en particulier,” in Comptes rendus hebdomadaires des séances de l’Académie des sciences, 145 (1907), 1025.