ROUX, PIERRE PAUL ÉMILE

(b. Confolens, Charente, France, 17 December 1853; d. Paris, France, 3 November 1933) bacteriology.

Roux was one of the principal founders of medical bacteriology, both through his collaboration with Pasteur and his own achievements. After attending secondary school in Aurillac and in Puy, he began his medical studies at Clermont-Ferrand. There he met Émile Duclaux, who imparted to Roux his enthusiasm for Pasteur. To complete his studies, Roux went to Paris, where in November 1878 he was accepted as an assistant at Pasteur’s laboratory. With Chamberland and Thuillier he became associated in Pasteur’s research on the etiology of anthrax and then on the attenuation of viruses, the basis for the preparation of Pasteur’s vaccines.

After the perfection of vaccines against chicken cholera and anthrax, research on the prevention of rabies was begun. The difficulties were particularly great, since the pathogenic agent, or rabies virus, remained unknown. Roux succeeded in producing experimental cases of rabies (especially in rabbits), which displayed a regular sequence of development (by selecting a virus fixe). The virulence of a rabic medulla could then be diminished under certain conditions.

When the Institut Pasteur was created in 1888, Roux was placed in charge of instruction in microbiology. At the same time, he became director of the Service de Microbie Technique and began his most important original work. First, lie confirmed the pathological role of the diphtheria bacillus, discovered shortly before in Germany by Klebs and Loeffler. With the bacillus he was able to reproduce paralysis experimentally in guinea pigs. Finally, and perhaps most important, he demonstrated with A. E. J. Yersin that the pathogenic power of this bacillus depends not merely on its presence but, rather, on a poison, or toxin, that it produces. This toxin spreads throughout an organism, and, in Roux’s words, “snake venoms themselves are not as deadly.” Soon afterward an analogous toxin, produced by the tetanus bacillus, was discovered by Knud Faber in Denmark.

In the course of their research to transform bacterial toxins into vaccines, a fundamental discovery was made in Berlin by Behring and Kitasato: a counterpoison (or antitoxin) forms in the serum of animals which have received quantities of toxin too weak to kill them and this serum can be used to protect other animals against an injection of a quantity which would otherwise certainly be fatal. It seemed curious, however, that among human beings the protection derived in this manner proved to be comparatively weak.

For that reason, Roux began to study the subject once again. Putting aside for the moment antitetanus serotherapy, he devoted all his efforts to investigating diphtheria. Working with horses, he determined the best conditions (1892–1893) for obtaining an antidiphtheritic serum; and in 1894, with the aid of Louis Martin and Auguste Chaillou, he treated diphtheritic children with this serum. The results, presented later that year to the Tenth International Congress of Hygiene in Budapest, evoked a response famous for its enthusiasm. The disease was completely conquered after the discovery of Gaston Ramon’s vaccine, the anatoxin.

Roux’s personal work was almost completely interrupted when, upon the death of Duclaux (1904), he became director of the Institut Pasteur. He held this post until he died, subordinating his own work in order to be of more help to those under him.

BIBLIOGRAPHY

I. Original Works. Roux wrote very little. His memoirs written with Pasteur before 1890 were published in the Comptes rendus hebdomadaires des séances de l’Académie des Sciences et de l’Academie de médecine. Several later papers (1904–1933) can also be found there. His most important investigations were presented in the Annales and the Bulletin de l’Institut Pasteur (until 1903). The most important are “Contribution à 1’étude de la diphtérie,” in Annales de l’Institut Pasteur, and “Trois cent cas de diphtérie traités par le serum antidiphtérique,” ibid.

II. Secondary Literature. Numerous studies have been devoted to Roux. A list of these is given in A. Delaunay, L’Institut Pasteur, des origines à aujourd’hui (Paris, 1962). Two biographies should also be mentioned: M. Cressac, Le docteur Roux, mon oncle (Paris, 1950); and E. Lagrange, Monsieur Roux (Brussels, 1954).

A. Delaunay