Expression inEscherichia coli of a gene coding for epitopes of a diagnostic antigen ofParacoccidioides brasiliensis

A methodology to isolate nucleic acids from the human pathogenParacoccidioides brasiliensis was developed that enabled the construction of genomic libraries in bacteriophage λgt11. Among 3000 recombinant phage 20 were selected by hybridization with cDNA synthesized from mRNA isolated fromP. brasiliensis yeast forms, which correspond to the fungus phase found in infected tissues. One of these clones expressed an antigen which was specifically recognized by sera from patients with paracoccidioidomycosis. Antibodies isolated by adsorption to a lysate of this clone bound to the exocellular glycoprotein of 43 kDa (gp43). As shown previously (Pucciaet al., 1986,Infect. Immun.53: 199–206), this is the main diagnostic antigen of paracoccidioidomycosis.