Detection of Aspergillus and Penicillium extracellular polysaccharides (EPS) by ELISA: using antibodies raised against acid hydrolysed EPS.

ABSTRACT

Species of the fungal genera Aspergillus and Penicillium produce immunologically active extracellular polysaccharides (EPS) in which galactofuranose residues are immunodominant. The antigenic determinant of the EPS of A. fumigatus, A. niger and P. digitatum could be removed by acid hydrolysis. Due to the hydrolysis of the EPS the immunological reaction between IgG anti-native EPS and hydrolysed EPS disappeared. Antibodies raised in rabbits against the acid hydrolysed EPS revealed new antigenic determinants that were exposed as a result of the acid hydrolysis. Immunological inhibitory experiments showed that the antibodies were no longer directed to galactofuranose residues. Enzyme Linked Immunosorbent Assay, carried out with antibodies raised against the acid hydrolysed EPS showed that the antibodies against the acid hydrolysed EPS were more species specific in comparison with the antibodies against the native EPS.