The antigenic composition of Cryptococcus neoformans. V. A survey of cross-reactions among strains of Cryptococcus and other antigens.

Serologic methods are becoming increasingly important in the diagnosis of mycotic infections. Necessary prerequisites for the evaluation of such tests should include information on the antigenic relationships of strains within a species as well as relationships with other species, both closely and distantly related. Several investigations of interspecies cross reactions among fungi have appeared during the past few years (Campbell and Saslaw, 1948; Pates, 1948; Salvin, 1949, 1950; Saslaw and Campbell, 1948; Tenenberg and Howell, 1948). The existence of more than one antigenic type within the species Cryptococcus neoformans also has been reported (Evans, 1950). The possibility of using a serologic test in the diagnosis of cryptococcosis (Neill et al., 1951) suggests a need for further knowledge of the antigenic relationships among cryptococci and other microorganisms, particularly those likely to cause cerebrospinal infection. The purpose of this paper is to present information on cross reactions occurring among strains of C. neoformans and antigens of other microorganisms and higher forms.