XI International Meeting on Paracoccidioidomycosis

XI International Meeting on Paracoccidioidomycosis

Resume:131-3

Poster (Painel)

131-3

Morphological and ultrastructural differences between two different isolates (Pb 01 and Pb 18) of the fungus Paracoccidioides brasiliensis.

Authors:

Isaque Medeiros Siqueira (UNB - Universidade de Brasília) ; Ana Camila Oliveira Souza (UNB - Universidade de Brasília) ; Márcio Souza Jerônimo (UNB - Universidade de Brasília) ; Alice Melo Ribeiro (UNB - Universidade de Brasília) ; Carlos Antônio Inácio (UNB - Universidade de Brasília) ; José Raimundo Corrêa (UNB - Universidade de Brasília) ; Sônia Nair Báo (UNB - Universidade de Brasília) ; Maria Sueli Soares Filipe (UNB - Universidade de Brasília) ; Anamélia Lorenzetti Bocca (UNB - Universidade de Brasília)

Abstract

There is a great genetic diversity between different isolates of P. brasiliensis, after checking the genetic variability inside the species, it was testified that the isolate Pb 01 was located aside of the rest of the group, inclusively from isolate Pb 18. Trying to help the understanding of the real position of the Pb 01 within the genus, we realized this study, using optical microscopy as well as scanning and transmission electron microscopy, showing significant morphological and ultrastructural differences between these two isolates. Both isolates were cultivated in brain heart infusion broth during four to seven days showing numerous budding yeast cells that characterize the typical pattern of “old boat steering-wheel”, however they differ in the form and size of their structure. Pb 01 mother cells sometimes appear as globose-elliptical to globose, rather globose, denser in microfibrils, hyaline and smooth. The diameter of the Mother-cells ranged from 4 to 27 μm. Daughter cells appears as globose to cillindrical-clavate, attenuating towards to the basal portion where it is connected to the mother-cell, later becoming broad clavate to globose. Its diameter ranged from 1 to 16 μm. Pb18 mother cells show sometimes globose-elliptical to elliptical, rather elliptical, and hyaline, smooth having at margins few budding daughter cells, raging its diameter from 4 to 25 μm. Daughter cells are elliptical-clavate attenuated at basal portion where it is connected to the mother-cell, then becoming cillindric-elliptical to broad elliptical. Its diameter ranged from 2 to 29 μm. In order to complement the obtained data, we observed also differences in fungal infection triggered by these two different isolates. Thus, further studies are being conducted to identify differences between the two strains in vivo.

Keyword: isolate Pb 01, Isolate Pb 18, Morphology, Ultrastructure

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