ADIASPIROMYCOSIS IN SUSPECTED CASES OF PULMONARY TUBERCULOSIS IN THE COMMON BRUSHTAIL POSSUM (TRICHOSURUS-VULPECULA)

Pulmonary adiaspiromycosis was diagnosed in 15 of 17 common brushtail possums (Trichosurus vulpecula) examined for bovine tuberculosis. Emmo nsia crescens was isolated from two of the affected animals. This is t he first reported isolation of this dimorphic fungus in New Zealand. T he infections varied from light to heavy with sparsely distributed, fo cal, 1-2 mm diameter, grey-white spherical granulomas in the lightly i nfected cases to innumerable foci throughout the lungs in the heavily infected cases. Histologically, the lesions were characterised by a ce ntral fungal adiaspore consistent in morphology with E. crescens locat ed in alveolar spaces or bronchioles. These were surrounded by a cuff of granulomatous inflammation which varied in density and extent in pr oportion to the degree of degeneration exhibited by the organism. The lesions in most cases of adiaspiromycosis in the possum are sufficient ly distinctive to allow their differentiation from tuberculosis by gro ss examination, but where any doubt exists over the possibility of dua l infection by Emmonsia and Mycobacterium species differentiation shou ld be made on the basis of a histological examination of the tissue an d culture for mycobacterial organisms.