Fructose-bisphosphate aldolase and pyruvate kinase, two novel immunogens in Madurella mycetomatis

Abstract

Eumycetoma, a chronic granulomatous disease characterized by a subcutaneous mass, multiple sinuses and purulent discharge containing grains, remains difficult to diagnose and treat. Madurella mycetomatis is the most common causative agent of eumycetoma. Using a serum pool from patients with active mycetoma, we screened a M. mycetomatis-specific λgt11 cDNA library which was shown to contain 8% of cDNA inserts encoding proteins involved in glycolysis. Two of these enzymes, fructose-bisphosphate aldolase (FBA) and pyruvate kinase (PK), were produced in vitro and their antigenicity was studied with bead-based flow cytometry. It appeared that both FBA and PK IgG antibodies were present in eumycetoma patient sera. However, only FBA antibody levels were found to be significantly higher in eumycetoma patient sera when compared to healthy Sudanese controls. Furthermore, FBA and PK were also found to be expressed on the hyphae present in the mycetoma grain. In conclusion, this study presents two new antigenic proteins of M. mycetomatis next to the translationally controlled tumour protein (TCTP): the glycolytic enzymes FBA and PK. These antigens might be useful as vaccine-candidates in the prevention of mycetoma.