AN EXOANTIGEN TEST FOR THE RAPID IDENTIFICATION OF MEDICALLY SIGNIFICANT FUSARIUM SPECIES

The accurate identification of Fusarium species can take 2-3 weeks. Pr eliminary exoantigen studies indicate that a mature culture suspected of being a Fusarium species may be immunologically identified 48 h aft er receipt. Exoantigen extracts of 10-day-old slant cultures of Fusari um chlamydosporum, Fusarium moniliforme (= Fusarium verticilloides), F usarium oxysporum, Fusarium proliferation and Fusarium solani and part ially purified reference homologous and heterologous shake culture ext racts (6-week-old) were reacted against rabbit ant-F. chlamydosporum, F.moniliforme, F. oxysporum, F. proliferatum and F. solani sera, in a micro-immunodiffusion procedure. The results indicated that all the st rains belonging to a given species produced 1-3 bands of identity only when tested against its homologous antiserum and reference antigen. N o cross-reactions were observed with the heterologous antisera. Furthe rmore, extracts from isolate of Fusarium dimerum, Fusarium equiseti, F usarium roseum complex, Acremonium species, Cylindrocarpon, Fonsecaea pedrosoi and Trichoderma species did not react with any of the prepare d Fusarium species' antisera. Our data suggest that the exoantigen pro cedure is a rapid and reliable tool for the accurate immuno-identifica tion of the medically Fusarium species studied.