We analysed the hydrolysis of 23 amides by 500 yeast and yeast-like st
rains isolated from clinical specimens, identified to species level by
conventional methods, in order to verify the validity of this method
of species identification. The results show that 10 of these amides (a
cetamide, acrylamide, alaninamide, formamide, glycinamide, propionamid
e, urea, thioacetamide, thiourea and valeramide) are sufficient to dif
ferentiate seven genera and 19 species, with an occasional requirement
for three additional tests: cycloheximide susceptibility, surface fil
m formation on liquid medium and ascospore formation. The study of the
amidase activity in yeasts and yeast-like fungi seems to be a promisi
ng method of identifying strains isolated from clinical samples.