ABSTRACT
Paracoccidioides brasiliensis is a pleomorphic organism which depends on the temperature of growth for the expression of its morphology. While the maintenance and development of either the Y or the M form may require of specific nutritional sources, the transition between morphological phases in P. brasiliensis depends exclusively on temperature and is independent of the nature or composition of culture media. One of the first experiments performed to relate Paracoccidioides brasiliensis dimorphism with any biological function was that of W. J. Nickerson and G. A. Edwards. Other aspect that concerns the regulation of dimorphism and the expression of pathogenicity is the involvement of the cell wall during transformation. The possibility that, in arresting M to Y transformation in P. brasiliensis, ajoene behaves like an —SH-blocking agent, brings a parallelism with the same use of p-chloromercuryphenyl-sulfonic acid (PCMS) on M to Y phase transition in H. capsulatum.
