Serological and antigenic profiles of clinical isolates of Paracoccidioides spp. from Central Western Brazil

Abstract

Clinical Paracoccidioides spp. isolates from patients with paracoccidioidomycosis (PCM) in Mato Grosso, Brazil exhibit different patterns of serologic reactivity. The results observed for reactions of radial immunodiffusion against the commonly used exoantigens containing a 43-kDa glycoprotein (gp43) suggest that this fungus exhibits major antigenic variability by geographic region. There is a phylogenetic gap between Paracoccidioides spp. isolates among different regions of Latin America. In particular, those from the central region of Brazil (i.e. Mato Grosso state) exhibit a lower rate of genetic similarity. We aimed at investigating the phylogenetic classification of clinical isolates of Paracoccidioides spp. in Central Brazil and the different antigenic profiles that produce. Exoantigens were obtained from five clinical isolates: two P. brasiliensis (Pb166 and Pb2880) and three P. lutzii (PL2875, PL9840, and PL2912). The protein/glycoprotein profiles of P. lutzii exoantigens were different from each other. Isolate PL9840 exhibited the most distinct bands, and isolates PL2875 and PL2912 exhibited more diffuse bands and a very intense band between 50 and 60 kDa. P. brasiliensis isolates had similar protein profiles, exhibiting a low-intensity band at 220 kDa and a diffuse band between 50 and 60 kDa. P. lutzii isolates exhibit high species-specific antigen variability, which we have already been assessed in proteomic studies.