FINE-STRUCTURE AND CYTOCHEMICAL STUDY OF THE INTERACTION BETWEEN FONSECAEA-PEDROSOI AND RAT POLYMORPHONUCLEAR LEUKOCYTE

The induction of a granulomatous reaction is frequently observed in su bcutaneous mycoses. Our previous studies demonstrated that Fonsecaea p edrosoi was able to survive and proliferate in tissue macrophages and that activated macrophages were fungistatic but not fungicidal. By con trast, our present studies revealed that neutrophils were able to kill F. pedrosoi cells in periods shorter than 20 min. Several phases of t he interaction process were analysed by light and electron microscopy. The kinetic analysis demonstrated no significant difference during th e first hour of F; pedrosoi-neutrophil interaction. Electron microscop y images showed that neutrophils readily associated with and killed ex tracellular fungi; however, few fungi were ingested. During this proce ss the activation of respiratory burst took place as evaluated by ligh t and electron microscopy. Cytochemical activity of acid and alkaline phosphatase was detected in low levels during the host cell-parasite i nteraction.