Treatment of experimental Cryptococcus neoformans infection in newborn rabbits by airway instillation of specific antibody and surfactant

Animal models: an important tool in mycology

Animal models of fungal infections are, and will remain, a key tool in the advancement of the medical mycology. Many different types of animal models of fungal infection have been developed, with murine models the most frequently used, for studies of pathogenesis, virulence, immunology, diagnosis, and therapy. The ability to control numerous variables in performing the model allows us to mimic human disease states and quantitatively monitor the course of the disease. However, no single model can answer all questions and different animal species or different routes of infection can show somewhat different results. Thus, the choice of which animal model to use must be made carefully, addressing issues of the type of human disease to mimic, the parameters to follow and collection of the appropriate data to answer those questions being asked. This review addresses a variety of uses for animal models in medical mycology. It focuses on the most clinically important diseases affecting humans and cites various examples of the different types of studies that have been performed. Overall, animal models of fungal infection will continue to be valuable tools in addressing questions concerning fungal infections and contribute to our deeper understanding of how these infections occur, progress and can be controlled and eliminated.

Trypanosoma lewisi-induced immunosuppression: The effects on alveolar macrophage activities against Cryptococcus neoformans

The immunosuppressive effect of Trypanosoma lewisi infection on alveolar macrophage (AM) activities against Cryptococcus neoformans was studied in an animal model. Two groups of rats were treated with T. lewisi and killed after 4 (4d-rats) and 7 days (7d-rats), respectively. A third group not given T. lewisi, served as control. AM were challenged in vitro with C. neoformans. Phagocytosis was assessed with a fluorescence method. Superoxide anion production was evaluated with the nitroblue tetrazolium (NBT) test. The survival of cryptococci was estimated by counting colony-forming units. The numbers of detached AM from culture plates were determined using a Bürker chamber. The NBT response, adhesion to plate surface and killing activity, but not the phagocytosis of AM from 4d-rats were significantly impaired compared to control or 7d-rats. Thus, T. lewisi causes transitory immunosuppressive effects on AM activities. This rapid T. lewisi immunosuppression model may be useful to study new approaches to anticryptococcal therapy.