ANTIFUNGAL ACTION OF ANTIBIOTICS 297 



mococcus type. The polysaccharidase destroys the protective capsular 

 substance of the pneumococcus, thus rendering it susceptible to phagocy- 

 tosis. 



The toxicity of many other antibiotics to animal tissues prevents their 

 consideration as potential chemotherapeutic agents. The range of tox- 

 icity and type of effect vary considerably, from the highly toxic acti- 

 nomycin (796) to those which are characterized by lesser but still 

 considerable toxicity, such as citrinin (18). 



Virulent strains of M. tuberculosis were found to lose their virulence 

 in the presence of certain other organisms or their products. According 

 to Vaudremer, this phenomenon occurs when the tubercle organism is 

 kept for 24 hours at 39° C. in contact with a filtered extract of A. 

 jum'igatusy and a similar effect can be exerted by certain bacteria. On the 

 other hand, extracts of A . fumigatus were used for the treatment of 200 

 tuberculous patients, with rather inconclusive results (740, 934). 



Treatments of intestinal disturbances by the use of antagonistic micro- 

 organisms, although highly promising, have not been sufficiently in- 

 vestigated as yet. It may be of interest to note, in this connection, that 

 the presence in human intestines of E. coli with a high antagonistic in- 

 dex is considered as important evidence of immunity of certain indi- 

 viduals to intestinal disturbances (387, 618, 661, 681). 



ANTIFUNGAL ACTION OF ANTIBIOTIC SUBSTANCES 



The ability of certain antibiotic substances to inhibit the growth of 

 various fungi has been brought out previously. For test purposes, a 

 strain of Trichophyton mentagrofhytes (T. gyfseum) is used (240). 

 The fungus is grown on a peptone-glucose agar medium of f¥L 5.6 to 

 5.8, and a spore suspension prepared from ten-day-old mycelial growth 

 by shaking with glass beads. The spore suspension is then streaked over 

 agar plates containing varying concentrations of the antibiotic, or added 

 to a series of tubes containing graded concentrations of the agent, in a 

 manner similar to determination of phenol coefficient, 



(Although a large number of substances are thus found to have 

 definite activity, they vary greatly in their usefulness because of vari- 

 ation in toxicity. Some, like actinomycin, are extremely toxic j others, 



