146 FUNGI AS ANTAGONISTS 



Basidtomycetes 



The larger Basidiomycetes produce bacteriostatic substances that 

 compare favorably with those formed by Aspergilli and Penicillia. The 

 testing of the sporophore extract alone may be indicative, but it is not 

 a fully reliable test for a positive result j the fungus must be cultured 

 and a strip test made (1014). Of 700 species tested, about 70 gave a 

 strong positive reaction and lOO a weak reaction against S. aureus 

 and/or E. coU (1019). In a comparison of 72 genera, one or more 

 species of 43 genera produced some antibiotic activity j none, however, 

 was more active than P. notatum and none affected gram-negative 

 forms (785, 785a). 



Polyporin, produced in the culture filtrate and in the sporophores of 

 Polystktus sanguineus y is a thermostable substance not affected by ^H 

 changes between 2.0 and 8.0. It passes through a Seitz filter, is not af- 

 fected by body fluids, is nontoxic, and is active in vitro and in vivo 

 against various gram-positive {S. aureus j S. viridans) and gram-nega- 

 tive bacteria {E. ty^hosa, V. comma, etc.). Clitocybe gigantea var. 

 Candida, a member of the Agaricus group, contains in its cell material a 

 substance, designated as clitocybin, which is soluble in water, chloro- 

 form, acetone, and ether. It is destroyed on heating at 70° to 80° C. It 

 inhibits the growth of various gram-negative bacteria, such as E. coli, 

 Ps. aeruginosa, E. tyfhosa, and Br. abortus, various gram-positive bac- 

 teria, and M. tuberculosis. It is fairly toxic to animals: i gm. of the dry 

 fungus substance is treated for 24 hours with 10 ml. water j i ml. of this 

 extract will kill a 300 gm. guinea pig in 48 hours. It is effective in ar- 

 resting the development of tuberculosis in guinea pigs (439). Several 

 species of Cortinarius and one of Psalliota inhibited various gram-posi- 

 tive and gram-negative bacteria (30). 



Other Groufs 



Various other fungi, including A . albus, A . niger, and Monilia albi- 

 cans, were found (1051) to exert a marked antibacterial action against 

 human and bovine tubercle bacteria 5 active filtrates were obtained, but 

 the specific agents were not isolated. Certain dermatophytes, especially 

 strains of Trichophyton mentagrofhytes, also produce an antibiotic 



