PATHOGENESIS OF COCCIDIOIDES IMMITIS IN MONKEYS

Abstract

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

Experimental Animal Models of Coccidioidomycosis

“…18,19 Overall, in numerous studies, in mice and other animal species, the course of infection has been shown to be progressive with increases in the fungal burden in the organs, and increases in organ weight. 1,[17][18][19][20][21][22][23][24][25][26] The relative virulence of a pathogen is determined by both the organism and the host. For Coccidioides, differences in the virulence of strains have been shown in murine models of infection.…”

“…1,2,5,34,[42][43][44] In early studies by Savage and Madin, 45 the cellular response in the lungs of vaccinated mice was examined after intranasal challenge and suggested the involvement of macrophages as cells better able to kill infecting arthroconidia; similar histopathologic studies of vaccinated animals were done by several other investigators, demonstrating the development of the granulomatous response. 20,24,46 T cell-deficient nu/nu mice, which are unable to mount an effective adaptive immune response, were highly susceptible to infection, and macrophages were particularly important to resistance of previously immunized mice in comparison with normal control mice, whereas PMN dysfunction in bg/bg mice did not appear to play as significant a role in resistance. 18,43,47 The host response of DBA/2 mice has been shown to be directed toward a protective Th1 response, related to interleukin (IL)-12 and interferon-␥ , whereas susceptible BALB/c exhibit a Th2 response, related to IL-4 and IL-10, and less resistance to infection.…”

A Risk Analysis for Airborne Pathogens with Low Infectious Doses: Application to Respirator Selection Against Coccidioides immitis Spores

“…Published data on airborne infection by C. immitis spores are sparse. Approximately 40 years ago, U.S. Army researchers conducted experiments in which small groups of Rhesus monkeys ( Macaca mulatta ) were exposed to different spore aerosol concentrations (25–27) . These data are summarized in Table I.…”

“…Inhalation of 10 spores infected all animals, whereas the severity of the infection sequela was dose dependent. For example, among five monkeys inhaling 50 spores, the lung lesions were localized with little destruction of lung tissue and dissemination to lymph nodes, and no deaths occurred; in three of five monkeys inhaling 300 spores, there was extensive pulmonary disease resulting in death (27) …”

Experimental epidemiology of coccidioidomycosis.

“…There was no clinical, serological, radiological, histological, or cultural evidence of coccidioido- a Numbers refer to aerosol arthrospore dose (experimental; references 4,14). These data represent a total of 50 monkeys, at 5 to 10 monkeys per dose group.…”