Naturally Acquired Leprosy-Like Disease in the Nine-Banded Armadillo ('Dasypus novemcinctus'): Histopathologic and Microbiologic Studies of Tissues.

摘要

Histopathologic studies were conducted on tissues from necropsies on 41 nine-banded armadillos from Louisiana with a natural disease resembling lepromatous leprosy, hereafter often referred to as the 'natural disease.' The lesions were composed of macrophages (histiocytes) containing numerous acid-fast bacilli and were similar to those seen in armadillos experimentally inoculated with Mycobacterium leprae. Invasion of small and large nerves by phagocytes containing acid-fast bacilli was a characteristic feature of the natural disease. The Mycobacterium presumed to cause the disease was not cultivable on standard mycobacterial media; however, mycobacteria belonging to the M. aviumintracellulare group were cultivated from lymph nodes of 8 and the spleen of 1 of 32 of the diseased armadillos but not from other organs. Cultures of lymph node specimens and other organs from each of the remaining 24 diseased armadillos were negative. Acidfastness of the bacilli in all tissues was abolished on exposure to pyridine. The bacilli were DOPA oxidase positive, but interpretation of this finding is difficult because some tissues from normal armadillos also gave positive reactions in the spot test employed. Histopathologic studies of tissue from autopsies on the 41 armadillos and microbiologic studies on tissues from 32 of the animals provided evidence indicating that the cause of the natural disease in armadillos may be M. leprae. (Author)