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Purpose. Chromomycosis is a tropical disease caused by several melanized dimorphic fungi, Cladophialophora carrionii and Fonsecaea pedrosoi being the most frequent agents. Epidemiological studies in the semi-arid area of northwestern Venezuela suggested that this mycosis should be considered as a multifactorial disease related to susceptibility of some familiar groups.

Materiel. Methods. We considered it interesting to examine the immune response in murine model against chromomycosis agents. CD1 mice and inbred DBA2, BALB/C, 57BL 10, C57 BL 6, C3H, C3H/He JCR, were inoculated subcutaneously once or twice with CI. carrionii or F. pedrosoi. Inflammation of the foot were compared. Fungus survival in foot, liver and spleen was rested. Antibody production was measured by indirect immunoflurescence.

Results. After three weeks, inflammation was observed in all mice. No local apparent lesion were observed in any mouse strains within sixteenth weeks. Negative liver and spleen cultures confirmed that no dissemination occured. Antibodies against Cl. carrionii or F. pedrosoi were detected from the sixteenth week after inoculation. Antibodies were fixed on the young portions of mycelium only, suggesting a protective role of melanine against humoral immune response survival of fungi appeared unrelated to humoral immune response. We confirmed that the virulence of these two dematiaceous fungi is extremely low in murine model. Cell-mediated immunity of the families affected by the disease at Venezuela endemic zone should be investigated.