Friedrich August Loeffler was a German physician who turned his career path to focus on microbiology after becoming an assistant to Robert Koch. Loeffler is accredited with the discovery of several microorganisms including Loefflerella mallei, the etiological agent of glanders, Corynebacterium diphtheriae, the infectious organism of diphtheria; and Erysipelothrix rhusiopathiae, the infectious agent that causes cholera in swine. In addition to his discoveries of bacteria, Loeffler determined that foot-and-mouth disease was due to an infectious microorganism smaller than any bacteria (a virus).

Friedrich Loeffler began his studies in medicine at the University of Würzburg but then transferred to the Army Medical School shortly before the Franco-Prussian War. In 1872, Loeffler received his medical degree and then worked as an assistant physician in Berlin at the Charté Hospital. Beginning in 1876, he worked as a public health officer and military surgeon in Potsdam and Hannover. This lasted until...