Host-parasite relationships in the yeastlike form of Paracoccidioides brasiliensis strain IVIC Pb9

Abstract

The yeastlike form of Paracoccidioides brasiliensis strain IVIC Pb9 reduced the amount of a-1,3-glucan in its cell wall from 45 to 3% when subcultured in vitro for several years. This strain regained its a-1,3-glucan up to 25% of the total cell wall when grown in vivo. A mutant strain of P. brasiliensis Pb9, named IVIC Pbl4O, reported to have 1,3-mannan instead of a-glucan in the cell wall, could not be recovered from experimentally infected animals. The existence of some relationship between the presence of a-1,3-glucan in the cell wall of the yeastlike form and the pathogenicity of this fungus is suggested in this report.

Influence of Serum on in Vitro Digestion of Paracoccidioides brasiliensis by Neutrophils

“…Digestive ability of PMNs was significantly greater in all groups against Pb-9 than against 6688 (P < 0.001 ). This result is consistent with previous findings (5) and might be explained by the fact that Pb-9 has a defective cell wall ( 12).…”

Dynamics of cell wall components of Magnaporthe grisea during infectious structure development

“…(2007) has presented evidence that α‐1,3‐glucan masks β‐glucan on the cell wall of Histoplasma capsulatum to block host recognition of the fungal invasion. A correlation between reduction in α‐1,3‐glucan and virulence has also been observed in other dimorphic fungal pathogens, such as Paracoccidioides brasiliensis and Blastomyces dermatitidis (San‐Blas et al ., 1977; Hogan and Klein, 1994; Rappleye and Goldman, 2006). Similarly to the case of H. capsulatum , it has been assumed that the fungal α‐1,3‐glucan conceals cell wall MAMPs on the fungal cell surface to circumvent recognition by hosts (Hogan et al ., 1996; Rappleye and Goldman, 2006).…”

Tumour necrosis factor productionin vivoandin vitroin response toParacoccidioides brasiliensisand the cell wall fractions thereof

“…Cell wall components have been associated with the dimorphism and virulenee of^ P. hrasiliensis [5,28]. a-gluean has been strongly implicated in the virulence of the fungus [29]. This polysacchiiride exists only in the parasitic yeast form of lhc fungus, but not in the myeelial form.…”