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.

Brazilian guidelines for the clinical management of paracoccidioidomycosis

“…Mato Grosso and Rondônia) exhibit a lower rate of genetic similarity. Yet, P. lutzii isolates exhibit high speciesspecific antigen variability 9 , which has already been assessed in proteomic studies.…”

“…P. lutzii encompasses a single species and is predominantly distributed in the Central West and Amazon regions of Brazil and Ecuador 1,5,6,7,8 . However, the real incidence of each phylogenetic species and its implication on clinical practice is difficult to establish because of the lack of guided studies comparing PCM forms and manifestations with their genetic background 9 . Radial immunodiffusion against the commonly used exoantigens containing a 43-kDa glycoprotein (gp43) suggests that Paracoccidiodes spp.…”

Paracoccidioides Species Complex: Ecology, Phylogeny, Sexual Reproduction, and Virulence

“…In addition to clinical manifestation, issues addressed to treatment have been raised by Hahn et al [40] who found that patients infected with P. lutzii had good responses to trimethoprim-sulfamethoxazole while those infected with P. brasiliensis relapsed with the same drug administration. Moreover, there are known to be a high number of patients coming from the north-central region of Brazil with PCM with low or no immunoreactivity [41], [42]. Immunodiffusion tests with antigens produced by isolates from São Paulo ( P. brasiliensis strain 339) crossed with sera from patients of Mato Grosso have low positivity (Figure 1B).…”

Comparison of virulence betweenParacoccidioides brasiliensisandParacoccidioides lutziiusingGalleria mellonellaas a host model

“…69 Recent studies have demonstrated that gp43 is highly specific for PCM caused by P. brasiliensis and false negative for P. lutzii. 70,71 By analyzing the peptide sequence of gp43 protein in both species, an 81 % similarity was found; however, the molecular models show differences between them. Specifically, the N-glycosylation site is absent, and the glucanase site and its enzymatic activity are preserved in gp43 from P. lutzii.…”