Serum-proteins as nitrogen source for yeastlike fungi

Abstract

Investigations have been made on the growth of Candida albicans and Cryptococcus neoformans in relation to serum proteins. Auxanographic techniques showed that some strains of C. albicans utilised human albumin at pH 4.6–5.5 and others did not. All strains of C. neoformans were negative. Proteolysis was demonstrated on serum protein agar at pH 4.6–5.5 and was shown to be dependent on the pH value. The method afforded reliable strain differentiation of C. albicans. Strains with the strongest proteolytic action also grew in liquid media with serum albumin as the sole nitrogen source as well as in control media with peptone. The significance of these findings in relation to human infections with yeasts is discussed.