Roux, Pierre Paul Émile

Roux, Pierre Paul Émile (pyĕr pōl āmēl` r), 1853–1933, French physician and bacteriologist. He was a pupil of and coworker with Pasteur. In 1888 he and A. E. J. Yersin demonstrated that the diphtheria bacillus produces a toxin; this led to the development by E. A. von Behring of methods of producing a specific antitoxin, which revolutionized the treatment of diphtheria. Roux worked with the veterinarian E. I. C. Nocard in the study (1898) of bovine pneumonia and with Élie Metchnikoff on syphilis.