Alanto-chorionic system in the study of infectious agents. I - Experimental achievement of paracoccidioidal granulomatosis (South American blastomycosis) in embryonate eggs

Abstract

Chick embryos can be infected by cultures of Paracoccidioides brasiliensis, variant strain cerebriform; Typical and constant lesions are produced within a few days; In both chorio-allantois or visceral allantois, lesions show a typically granulomatous character; Re-isolation cultures of fungi obtained from the lesions in chorioallantois or in visceral allantois grow in 6 days when kept at 37^oC, and in 7 days at room temperature; Direct examination of the material from those lesions discloses an enormous amount of Paracoccidioides; The type of the lesion produced in the visceral allantois, and the fact that this membrane is a very thin one, makes it possible to study the fungus just as it presents itself in the tubercules, without damaging its morphology by sectioning or like procedures; The allantoic fluid from eggs inoculated into this fluid reveals to be infectious to mice, when injected intraperitoneally. The mice when killed after two months show increase of the mesenteric ganglions where many typical forms of fungi can be found; It appears from our studies that further observations on the morphology of the Paracoccidioides brasiliensis in granulomatous lesions are possible. At the same time the effect of various substances, such as chemotherapics and antibiotics, upon the etiological agent of the South-american blastomicosis can be studied by means of this new technique.