Development of an immunocompetent murine model of pulmonary infection due to Scedosporium apiospermum.

ABSTRACT

A pulmonary infection model due to Scedosporium apiospermum in immunocompetent mice was developed. BALB/c mice were infected by endotracheal intubation with 5 × 106 conidia/mouse and disease progression was evaluated on days 1, 3, 5, 7, 11, 16, 21, 30, 50 and 60 post-infection through quantitative culture and histopathological analysis of lungs, livers, spleens, brains, and kidneys. There was no extrapulmonary dissemination during the study nor shown to be a lethal infection. The fungal burden in lungs was maintained from day 1-5 and gradually decreased by day 30 post-challenge. On day 60, 30% of mice showed complete elimination of the fungus. Severe alterations in the lung tissue were observed, as well as the presence of conidia and hyphae surrounded by a cellular infiltrate composed mainly of neutrophils in the first days of the infection. The elimination of fungal cells and normal tissue morphology were recovered throughout the study.