Studies on Coccidioides immitis. XVII: Morphology of the parasite in relationship with the host immunoallergic condition in the experimental infection of the guineapig

Experimental coccidioidomycosis in hamsters. Disease kinetics and death curve in relation to infective dose

“…Disseminated coccidioidomycosis is a serious, chronic granulomatous disease whose incidence is increasing in endemic areas, particularly in the United States [ 5, 6]. Different species of animals and immunological conditions have been used to develop experimental models to study the physiopathological mechanisms of the disease [ 14–16, 25]. The early experiments conducted by Alejandro Posadas [ 26] showed, using a variety of warm‐ and cold‐blooded animals inoculated with C. immitis by different means, that cold‐blooded animals were refractory to infection.…”

“…The early experiments conducted by Alejandro Posadas [ 26] showed, using a variety of warm‐ and cold‐blooded animals inoculated with C. immitis by different means, that cold‐blooded animals were refractory to infection. Other studies have shown that experimental inoculation of the mycelial form of C. immitis leads to disseminated disease with variable mortality, which is dependent upon (a) the route of infection [ 1, 14]; (b) immunological status of the animal [ 25, 28, 29]; (c) the strain of C. immitis [ 30]; (d) animal species [ 15, 16, 22].…”

“…The Mycology Center of the Medical School at the University of Buenos Aires has conducted extensive model studies with rodents [ 1, 14, 15, 17, 21]. Studies on the Wistar rat demonstrated that intracardiac inoculation of 60 C. immitis arthroconidiae produces disseminated infection, which subsequently localizes and leads to chronic pulmonary coccidioidomycosis, showing epithelioid granulomas containing great number of spherules, and a low spontaneous death index; immunodiffusion has proved the presence of antibodies, as of day 14 post‐inoculation [ 17].…”

“…Lax epithelioid granulomas are seen very early in the course of the experimental infection and they become more compact after the third week of evolution. At this stage of the experimental infection the C. immitis spherules exhibited a mature appearance with a thick cell wall and mature endospores, which were different from the spherule observed in Wistar rats treated with cyclophosphamide; or in guinea‐pigs during the first 2 weeks post‐infection, which presented large spherules with thin cell wall and a great amount of immature endospores (protospores) [ 15, 26].…”

“…Most studies on the immunological aspects of C. immitis disease and its treatment have utilized mice [ 11, 12, 13]. Our laboratory has worked with mice [ 14], guinea pigs [ 15] and Wistar rats [ 16, 17].…”