Studies on haemagglutinins of Microsporum gypseum

Evidence for the lectin nature of some dermatophyte haemagglutinins

Several isolates of dermatophytes covering 13 different species were studied for their haemagglutination activity with erythrocytes of different origins (human, bovine, sheep, mouse and rabbit). The best results were obtained with rabbit erythrocytes. The specific haemagglutination activity of the fungal soluble extracts seemed to be closely related to the ecology of the fungi. Among the different carbohydrate (ose, polyol, osamine) and glycoprotein solutions used in the inhibition experiments, only N-acetyl-neuraminic acid and a sialoglycoprotein, the bovine submaxillary mucin (mucin type 1), showed an inhibiting activity, demonstrating the lectin nature of the haemagglutinins and the importance of sialic acids in the recognition process. Reduction of haemagglutination activity by pretreatment of rabbit erythrocytes with trypsin or neuraminidase solutions further supports this view.

Detection of lectin from Chrysosporium keratinophilum (Frey) carmichael and Anixiopsis stercoraria (Hansen) Hansen by inhibition of haemagglutination

Several strains of Chrysosporium keratinophilum and Anixiopsis stercoraria agglutinate the red blood cells of different origins (man, sheep, rabbit, mouse). The best agglutination was obtained with rabbit erythrocytes. The inhibition experiments by carbohydrate solutions (oses, osamines and glycoproteins) were performed with 3 haemagglutination units of these fungi and revealed the lectin nature of this haemagglutinin, as evidenced by the specific inhibiting activity of N-acetyl-neuraminic acid. Preliminary studies seemed to indicate that this lectin is a thermostable protein, and that the haemagglutination activity is calcium-dependent.