Paracoccidioidomicosis experimental del ratón inducida por vía aerógena

Abstract

A study was undertaken to determine the possibility of inducing paracoccidioidomycosis in mice exposed to the mycelial phase of P. brasiliensis. Two strains of the fungus, designated FG and LA, were grown separately in media favoring the production of spores by the mycelial phase. These were collected and used for nasal instillation of 328 cortisone treated-mice. Animals were observed for a period of 16 weeks and sacrificed periodically. Pulmonary infection was obtained in 38·1% of the animals, with dissemination to spleen and liver occurring in 14·3% of the cases. The infection was not lethal. One of the strains (LA) proved to be more virulent than the other inducing a more severe type of pulmonary infection. The results of the study indicate that the mycelial phase of P. brasiliensis can give rise, by the inhalatory route, to active murine infections.A study was undertaken to determine the possibility of inducing paracoccidioidomycosis in mice exposed to the mycelial phase of P. brasiliensis. Two strains of the fungus, designated FG and LA, were grown separately in media favoring the production of spores by the mycelial phase. These were collected and used for nasal instillation of 328 cortisone treated-mice. Animals were observed for a period of 16 weeks and sacrificed periodically. Pulmonary infection was obtained in 38·1% of the animals, with dissemination to spleen and liver occurring in 14·3% of the cases. The infection was not lethal. One of the strains (LA) proved to be more virulent than the other inducing a more severe type of pulmonary infection.

Se llevó a cabo un estudio con el objeto de determinar si era posible producir paracoccidioidomicosis en ratones inoculados por la vía aerógena, con la fase miceliar del P. brasiliensis. Se utilizaron 2 cepas del hongo (FG y LA), las que fueron cultivadas en medios que favorecen la producción de esporos. Estos últimos fueron recolectados y utilizados para la instilación nasal de ratones, 328 en total. Los animales fueron conservados por 16 semanas, siendo sacrificados periódicamente. Un 38·1% de los ratones adquirieron infección pulmonar demostrada por la presencia del hongo en el tejido y/o por su aislamiento en cultivo. Se observó diseminación al bazo y al hígado en el 14·3% de los casos. La infección producida no tuvo carácter letal. Una de las cepas (LA) demostró ser más virulenta dando lugar a infección pulmonar más severa. Los resultados del estudio permiten aceptar que la fase miceliar (saprofítica) del P. brasiliensis puede dar lugar, por vía inhalatoria, a una paracoccidioidomicosis activa, con invasión pulmonar primaria y diseminación secundaria a bazo e hígado.