Tuberculoid nodular thelitis in a dairy goat flock.

An unusual outbreak of teat/udder skin lesions occurred in a dairy goat flock in France. Lesions first appeared as circular, indurated, erythematous areas of skin and progressed to form dark raised haemorrhagic crusts and ulcerative plaques. Histopathological examination revealed marked granulomatous dermatitis with multifocal ulceration. The granulomatous inflammation, with frequent Langhans type multinucleated cells and central caseous necrosis, was indicative of mycobacterial infection. The presence of non-cultivable mycobacteria was confirmed by sequencing PCR products from DNA extracted directly from the lesions and sequences matched a novel mycobacterial pathogen closely related to M. leprae and M. lepromatosis and previously identified in cattle thelitis. The association of nodular gross lesions and tuberculoid granulomas on the teat and lower udder, and the presence of mycobacteria DNA support a diagnosis of tuberculoid nodular thelitis in goats due to mycobacterial infection.

Electron microscopic characteristics of actinomycetic agents having aetiological association with human leprosy and epizootic ulcerative syndrome of fish.

The transmission electron microscopic (TEM) studies of the human leprosy derived chemoautotrophic nocardio-form (CAN) bacteria and EUS derived CAN bacteria showed presence of double contoured cell-walls consisting of an electron transparent and a dense layer. The fibrillar structures on the surface of these CAN bacterial cells also suggested their similarity to the human tissue derived Mycobacterium leprae cells. These EM studies further revealed mycelial and coccoid bodies in all these bacteria as was observed originally.

A pathogenicity model for the agents of epizootic ulcerative syndrome (EUS) in fish.

Chemoautotrophic nocardioform (CAN) bacteria had been repeatedly isolated from fish with ulcerative disease syndromes (EUS) from the massive epizootics that had repeatedly occurred since 1988 in eastern India as the major or only pathogenic agent in the background of distinctive environmental and epizootic data. Since these isolates bear significant similarity to the human and rat leprosy bacilli, attempts had been made to demonstrate the pathogenicity of this fish pathogen in the "Swiss" strain of mice as a convenient model. The studies reveal that the fish CAN bacteria could produce pathogenic effects in mice similar to that of the rat leprosy bacillus.