W. L. HOLMAN 107 



found in the intestines of breast-fed infants, is responsible for inhibition of the growth 

 of other bacteria, and its acid products are thought to be mild stimulants to the bowel 

 walls. In the vagina, B. doederleini is believed to keep the reaction acid, thus inhibit- 

 ing the growth of contaminating bacteria. Landau' was the first to use fresh beer 

 yeast in the treatment of leucorrhea and considered the anticatarrhal action was due 

 to mechanical overgrowth, the using up of food material and the action of metabolic 

 products in injuring or destroying other bacteria, neutralizing the toxins and chang- 

 ing the reaction to acid. He suggested injecting cultures of this yeast into the bladder 

 in cases of cystitis with alkaline urine. Since this work there have been many sug- 

 gestions and a variety of bacteria used to obtain such biological inhibitory action. 

 The antagonistic action of B, acidophilus has been abundantly proved against putre- 

 factive anaerobes, B. coli, and many other bacteria. Schiller,^ with a strain of B. 

 acidophilus from a dog, found that it rapidly destroyed and dissolved many strains 

 of streptococci in fluid media and suggested this as a useful way to obtain bacterioly- 

 sis of cocci. He showed that this action was not due to lactic acid since it occurred in 

 alkaline media and filtrates from a glucose broth culture living or killed (by heat or 

 age) allowed a good growth of the streptococcus. The harmful substance was only 

 formed by the B. acidophilus in the presence of the streptococcus or its products. 

 Filtrates of the mixed culture, after thirty-six hours at 37° C. (when the streptococci 

 are killed), were as toxic as when living cultures of the bacilli were used. Strepto- 

 coccus cultures killed by heat or age had no toxic effect on living streptococci. He 

 considered the phenomenon an example of induced antagonism and reported other 

 examples in a series of four articles.-' In the first he used B. mesentericus and forced 

 on it an antagonistic action against streptococci by growing it with the latter in a 

 medium of poor-food value. It secreted a bacteriolytic substance which digested the 

 living bacteria as it would any other insoluble albuminous material, and the amount 

 depended on the number of sensitive streptococci present. It also acted when the B, 

 mesentericus had been removed by centrifugation and after evaporation and drying. 

 It was not completely specific. Schiller further showed that yeasts can be made an- 

 tagonistic against bacteria including B. tuber ctilos is if the medium contained sugars 

 but lacked nitrogenous materials. They acted in the same way as the foregoing, and 

 a more active bacteriolytic substance was secreted in the presence of more resistant 

 forms so that the enzyme induced by B. tuberculosis was even capable of attacking 

 beeswax. The reverse was also found. Bacteria (staphylococcus, B. typhosus, B. para- 

 typhosus, et al.) became antagonistic to yeasts in nitrogen-free media, and the secreted 

 cytolytic substance was similar to the foregoing but had no effect on coagulated serum 

 or egg albumin. This method of dissolving the yeast membrane he thought might be 

 of interest in the study of zymase. 



Donaldson^ during the war used a strain of B. sporogenes in the treatment of slow- 

 ly healing war wounds. The beneficial effects he ascribed, not to direct inhibition, but 

 to the removal by the proteolytic anaerobe of the dead tissue (the pabulum for the 



'Landau, T.: Deutsche »icd. Wchnschr., 25, 171. 1899. 



^Schiller, I.: Centralbl.f. Baktcriol., I, Orig., 73, 123. 1914. 



3 Schiller, I.: ibid., 91, 68. 1924; 92, 124. 1924; 94, 64. 1925; 96, 54, 1925. 



4 Donaldson, R.: /. Path. &° Bact., 22, 129. 1918. 



