Heinrich Albert Johne
On October 23, 1894, in the Oldenburg region of Germany, a farmer purchased a cow that failed to produce milk or gain weight satisfactorily. A local veterinarian by the name of Herr Frederick Harmes examined the cow and, noting the diarrhea and weight loss, suspected intestinal tuberculosis. The cow tested negative by the tuberculin skin test however. It died the following spring and Dr. Harmes sent its intestines, stomach, and omentum for examination to the Veterinary Pathology Unit in Dresden. There the tissues were examined by Dr. H.A. Johne and Dr. L. Frothingham, a visiting scientist from the Pathology Unit in Boston, Massachusetts. Using an acid-fast stain, abundant acid-fast (red staining) bacteria were seen throughout the inflamed tissues. Although the organisms resembled bacteria that caused tuberculosis, a sample of the infected tissue containing the organisms failed to cause disease when injected into guinea pigs. Johne and Frothingham concluded that the disease observed in the cow was caused by the bacterium that causes tuberculosis in birds (Mycobacterium avium) and, in recognition of the pathological similarity to intestinal tuberculosis (normally caused by the bacterium that causes tuberculosis in cattle, Mycobacterium bovis), proposed the name "pseudotuberculous enteritis" for the disease.