Pathogenesis of Coccidioides immitis in monkeys.

Converse, J. L. (U. S. Army Chemical Corps, Fort Detrick, Frederick, Md.), E. P. Lowe, M. W. Castleberry, G. P. Blundell, and A. R. Besemer. Pathogenesis of Coccidioides immitis in monkeys. J. Bacteriol. 83:871-878. 1962.-Respiratory exposure to arthrospores from the submerged growth of Coccidioides immitis, strain Cash, in liquid medium resulted in similar pathogenesis in monkeys to that of strain Silveira arthrospores harvested from solid medium. Infectivity of 100% was noted with doses of 50 to 10,000 arthrospores. The disease was characterized by loss of appetite and weight, malaise, and extreme respiratory distress accompanied by coughing, with the immediate cause of death being acute coccidioidal pneumonia. The pathological picture was one of extensive, progressive, destructive pulmonary disease in the higher dose levels and few, small, self-contained, fibrous lesions, with little destruction of lung tissue, in the low doses. This was correlated in general with the findings of serial X rays and serological tests. The presence of the parasitic phase (spherule and endospore) of the organism was noted in large numbers within the pulmonary lesions and bronchial exudates and was substantiated by cultural methods. Occasionally, hyphal elements of the saprophytic growth phase were noted around the periphery of residual cavitated areas of the lungs.