Cryptic species of Paracoccidioides brasiliensis: impact on paracoccidioidomycosis immunodiagnosis.

Gabriel Capella Machado,Thales Domingos Arantes,Daniela Vanessa Moris,Eduardo Bagagli,Luciane Regina Franciscone Silva,Rinaldo Pôncio Mendes,Raquel Cordeiro Theodoro,Adriana Pardini Vicentini

doi:10.1590/0074-0276108052013016

Gabriel Capella Machado, Thales Domingos Arantes + Show 6 more

Open Access

https://doi.org/10.1590/0074-0276108052013016

Copy DOI

Abstract

We aimed to evaluate whether the occurrence of cryptic species of Paracoccidioides brasiliensis, S1, PS2, PS3 and Paracoccidioides lutzii, has implications in the immunodiagnosis of paracoccidioidomycosis (PCM). Small quantities of the antigen gp43 were found in culture filtrates of P. lutzii strains and this molecule appeared to be more variable within P. lutzii because the synonymous-nonsynonymous mutation rate was lower, indicating an evolutionary process different from that of the remaining genotypes. The production of gp43 also varied between isolates belonging to the same species, indicating that speciation events are important, but not sufficient to fully explain the diversity in the production of this antigen. The culture filtrate antigen AgEpm83, which was obtained from a PS3 isolate, showed large quantities of gp43 and reactivity by immunodiffusion assays, similar to the standard antigen (AgB-339) from an S1 isolate. Furthermore, AgEpm83 was capable of serologically differentiating five serum samples from patients from the Botucatu and Jundiaí regions. These patients had confirmed PCM but, were non-reactive to the standard antigen, thus demonstrating an alternative for serological diagnosis in regions in which S1 and PS2 occur. We also emphasise that it is not advisable to use a single antigen preparation to diagnose PCM, a disease that is caused by highly diverse pathogens.

Highlights

The thermal dimorphic fungus Paracoccidioides brasiliensis belongs to the phylum Ascomycota and is the etiological agent of paracoccidioidomycosis (PCM) (Lacaz 1994), the most important systemic mycosis in Latin America
In addition to reacting with three sera that were non-reactive to the standard antigen, this antigen was capable of detecting the presence of antibodies in all samples reactive to B-339
Comparing the five antigen preparations, the antigen obtained from the Epm83 isolate had a reactivity profile similar to the profile observed for the standard antigen (AgB-339) against the serum samples from Botucatu

Summary

Introduction

The thermal dimorphic fungus Paracoccidioides brasiliensis belongs to the phylum Ascomycota and is the etiological agent of paracoccidioidomycosis (PCM) (Lacaz 1994), the most important systemic mycosis in Latin America This disease mainly affects male rural workers and is endemic from Mexico to Argentina (Franco et al 1993). DID evaluates humoral immunity, a direct correlation has been observed between a decrease in serum antibody levels, a decrease in interleukin (IL)-10 and an increase in IL-2 and interferon-gamma production by peripheral mononuclear cells in PCM patients (Benard et al 2001). These findings show the importance of serological tests in treating PCM patients. Studies have indicated that gp acts as a laminin receptor, favouring the adhesion, colonisation and propagation of the pathogen (Vicentini et al 1994, Gesztesi et al 1996, Mendes-Giannini et al 2006)

Objectives

Results

Conclusion