298 



DISEASE CONTROL 



like clavacin, less so. Only a few appear to offer definite promise (771, 

 883) for the practical control of fungus infections, notably hemipyo- 

 cyanin, gliotoxin, and streptothricin. In addition to clavacin and glio- 

 toxin, certain other fungus products appear to show some promising 

 action against fungi pathogenic to man. These include mycophenolic 

 acid and aspergillic acid (818). 



The possibility of utilizing antagonistic bacteria for the control of 

 fungi causing skin infections has also been suggested (129). 



TOXICITY OF ANTIBIOTIC SUBSTANCES 



The various antibiotic substances obtained from microorganisms vary 

 greatly in their toxicity to animals. The therapeutic use of many of these 

 agents, like actinomycin and clavacin, which are highly bacteriostatic, 

 may be considered as either entirely excluded for the present or limited 

 to local applications. Some substances, as pyocyanase, penicillin, and 

 streptomycin, are relatively nontoxic (790); others, like tyrothricin 

 (793), streptothricin, and fumigacin (788), are slightly toxic j and still 



TABLE 50. MAXIMAL TOLERATED DOSE FOR MICE OF VARIOUS 

 ANTIBIOTICS 



From Robinson (788). 



Note: Figures represent maximal tolerated dose in mgm./kgm. 



