350 PATHOGENIC YEASTS 



In a culture one finds small cells with homogeneous color and with 

 fine membranes intermingled with large cells containing a refractive 

 body in their centers. 



On glucose broth this species forms a heavy sediment and very 

 often a scum. On gelatin plates the surface colonies are round like 

 pinheads and the deep colonies smaller and of a yellow color. In 

 gelatin stabs this species forms a white moist layer and numerous 

 colonies. It does not produce liquefaction. On potato it gives a fine 

 thick pellicle. 



This yeast is pathogenic for guinea pigs and rabbits. 



CRYPTOCOCCUS GRANULOMATOGENES. Vuillemin 

 Syn.: SACCHAROMYCES GRANULOMATOGENES. San Felice 



Discovered by San Felice in nodules on the lungs of pigs, this 

 Cryptococcus possesses round or slightly oval cells with a variable 

 edge with contents either homogeneous or vacuolar, and with a bright 

 central granule. 



On glucose broth it produces a cloudiness very rapidly, and later 

 a scum. On gelatin plates it gives round white colonies. The sur- 

 face colonies are larger. On gelatin stabs it produces a white layer 

 a little raised, accompanied along the line of inoculation by a train 

 of small yellow colonies. No liquefaction is produced. On potato the 

 culture is elevated and slightly grayish in color. This yeast produces 

 a red pigment on honey and slices of pear. It is slightly pathogenic 

 for animals. 



CRYPTOCOCCUS NIGER (Maffuci and Sirleo). Vuillemin 



This species was discovered by Maffuci and Sirleo 1 in a pul- 

 monary myxoma from a guinea pig inoculated with the liver of an 

 embryo coming from a tuberculous mother. In the myxoma and in 

 cultures it possesses round or oval cells with a rather thick membrane 

 and a protoplasm supplied with nuclear bodies. The cells remain 

 attached two by two. 



On liquid media the vegetation forms a white deposit and no scum; 

 on gelatin streaks a whitish growth is secured; on gelatin stabs a 

 whitish growth but no liquefaction; on potatoes the colonies are 

 brown. This yeast produces alcoholic fermentation in beer wort and 

 ferments maltose. It develops between 15 and 40 C. It is patho- 

 genic for animals, but only for a time. Cultures sterilized by heat 

 are toxic for guinea pigs. 



1 Maffuci and Sirleo. Osservazioni ed esperim. intorno ad un Blastomiceti, 

 patogeno inclusione dello stesso nella cellula dei tessuti patologici, Policlinico. 1895. 



