YEAST-LIKE FUNGI OF HUMAN INTESTINAL TRACT 7 



tines of the healthy children there were as many blastomycetes as in those 

 affected with diarrhea; (2) The forms found in both conditions vary from 

 case to case and it cannot be maintained as many wish, that they always belong 

 to Saccharomyces cerevisiae, Saccharomyces ellipsoideus, etc.; (3) The blasto- 

 mycetes must, for the present, be regarded as accidental ingredients of the 

 feces, since in the same case observed at different periods they vary so extra- 

 ordinarily, and since in no case has any one succeeded in discovering a definite 

 form, whether in man or other animals, when these were affected with diarrhea ; 

 (4) Up to the present time it has not been possible to bring forward any evi- 

 dence which will go to show whether the yeasts present in the intestines have 

 any useful or harmful action on the gastro-intestinal functions." 



Ashford ('16) has made an extensive study of animal inoculation with his 

 sprue organism both by injection and ingestion. He explains his own nega- 

 tive results in his feeding experiments at an earlier date on the ground that 

 the organism concerned rapidly loses its virulence when kept on artificial lab- 

 oratory mediums. His positive results were obtained by the use of recently 

 isolated yeasts or those passed through susceptible animals. 



INVESTIGATION OF YEASTS IN THE HUMAN DIGESTIVE TRACT 

 OBTAINED FROM THE FECES 



The series of experiments which follows was planned to determine 

 the presence or absence and relative number of yeast-like organisms 

 in the human alimentary tract, and to discover any relation which 

 might exist between their presence and gastro-intestinal disturbances 

 of various kinds. They were intended to extend and supplement the 

 investigations of Ashford and others. In addition, it was hoped that 

 a study of such organisms as were isolated would furnish a means 

 of distinguishing the pathogenic yeasts from those harmless ones 

 accidentally present but frequently occurring in the feces. 



METHODS 



Mediums for Isolation. The fact that the feces contain such a large num- 

 ber of bacteria, as compared with the fungi, has made the isolation of the 

 latter group very difficult when using the ordinary culture mediums and 

 standard plating methods. For this reason, a medium which restricted the 

 growth of the bacteria had to be employed. The most useful medium for this 

 purpose is undoubtedly Sabouraud's agar, as suggested by Ashford ('15c). 

 Since the method of preparation has been somewhat modified and since the 

 standard textbooks on bacteriologic methods do not include the formula for this 

 valuable medium the following account is included: . 



Agar 20 grams 



Peptone 10 grams 



Glucose 40 grams 



Water 1 liter 



The agar, peptone, and water are mixed and dissolved in the usual way. The 

 medium is then titrated and rendered + 2 acid with normal hydrochloric acid. 

 Without further heating, the sugar is added and the medium tubed in previously 

 sterilized tubes. Care is necessary in sterilizing since the high acidity of the 



