Infectious Dermatitis in Man Produced by a Bacillus Related to Escherichia Formica

Abstract

A peculiar skin affection of the wrist in 2 greenhouse workers, father and son, came under our observation, and from the lesions of both patients a bacillus which seems responsible for the affection was recovered in almost pure culture. At the time of observation the lesions were several months old, having developed slowly in both cases after a diffuse cellulitis of the wrist. The lesions consisted of well circumscribed, round or oval, reddened and indurated, slightly raised patches (2 on the extensor surface of the right wrist in the father and 1 in the same place in the son), of about 2.5 cm. in diameter, presenting a rough surface studded (in the father) with small pustules. Histologically, the lesion was represented by a considerable hypertrophy of the epidermis and a dense cellular infiltration of the corium consisting chiefly of large and small lymphocytic cells, few leucocytes and occasional giant cells of the Langhans type; but in some places there was a predominating leu-cocytic infiltration with abscess formation. Smears from the lesions in both cases showed an abundance of Gram-negative bacilli, partly phagocytized and partly free, and a few Gram-positive cocci arranged like staphylococci. In cultures from both cases, on ordinary media, the bacillus grew abundantly and exclusively. From studies of the morphological, cultural, and chemical properties of the microorganisms, it does not seem possible to classify it with any of the known pathogenes. It is pathogenic for rabbits and guinea pigs, especially the latter in which intraperitoneal inoculation of 0.2 cc. of a broth culture caused death with peritonitis, multiple hemorrhages in the lungs, and bacteremia. Injections of killed cultures into rabbits gave rise to the formation of agglutinins and complement fixing antibodies.