no BACTERIAL ASSOCIATIONS 



morphology of the latter also changed toward a more homogeneous form on staining. 

 By the use of filtrates of each culture they could not discover any evidence that the 

 toxin of the former was able to neutralize diphtheria toxin in vivo or in vitro. If the 

 two are grown together, however, no toxin is formed, nor is there any if the filtrate of 

 the pneumobacillus growth is used to grow the B. diphtheriae. They suggested the 

 therapeutic use of filtrates. In later studies on a larger number of clinical cases Gate 

 et al.' and Chalier, Gate, and Grandmaison^ confirmed their impressions of the usual 

 mild course of these mixed infections. 



Van der Reis\ having demonstrated an antagonistic action of B. coli to B. diph- 

 theriae, showed that it was possible, by spraying B, coli into the mouth, to have it 

 colonize there. In nine cases it was still present after fifty-four days. A careful study 

 of the antagonistic activity of B. coli led him to conclude that there is formed a ther- 

 molabile, volatile, non-dialyzable, non-filterable, inhibitory substance not adsorbed 

 by charcoal, not identical with the normal metabolic products of the colon bacillus, 

 but that it may be a special toxic product. It was tried in acute cases of diphtheria by 

 means of sprays of B. coli and particles of B. coli agar with the result that the B. 

 diphtheriae disappeared more quickly than in controls. Carriers could also be rapidly 

 freed of their bacilli. On the other hand, Pesch and Zschocke,'' although confirming 

 the crowding out of the B. diphtheriae by B. coli in cultures, were unsuccessful in treat- 

 ing nasal carriers because the B. coli would not grow in the nose. Bloomfield^ failed 

 in his attempts to implant Friedlander's bacillus from carriers to non-carriers, and 

 even a foreign strain of the bacillus failed to establish itself in the throat of a carrier 

 of another strain. Pringsheim* studied the inhibiting effect of a strain of B. mesenteri- 

 cus vulgatus against a variety of bacteria but particularly against B. diphtheriae. He 

 found that B. typhosus, B. paratyphosus A and B, B. fecalis alcaligenes, B. coli, and 

 streptococcus were without effect on B. diphtheriae. B. pyocyaneus and an air staphy- 

 lococcus were strongly inhibitive. Staphylococcus aureus was mildly stimulating as 

 seen in larger colonies as was also a weakly sporing B. subtilis strain. On agar plates 

 the effect of his B. mesentericus was to produce a circular zone of inhibition and just 

 beyond this a ring of larger colonies. Filtered or heated cultures had no effect. Other 

 proteolytic bacteria had no such action. It was tried on patients but the results were 

 inconclusive. The findings of Zukerman and Minkewitsch' with B. mesentericus vul- 

 gatus were somewhat different. The antagonism was inherent in the bacillus and was 

 not increased by serial passage. It acted only on diphtheria and pseudo-diphtheria 

 forms and not against a long list of other bacteria. Many other spore-bearers were 

 either negative or but weakly active. Filtrates were very active, killing in four min- 

 utes, and were fairly heat resistant. 



' Gate, J., el al.: ibid., 86, 929. 1922. 



' Chalier, J., Gate, J., and Grandmaison, L.: Paris med., 61, 205. 1926. 



3 Van der Reiss: Miinchen. mcd. Wchnschr., 68, 235, 1921; Zlschr. f. d. ges. expcr. Med., 30, 

 1922. 



-• Pesch, K., and Zschocke, O.: Miinchen. med. Wchnschr., 69, 1276. 1922. 



sBloomfield, A. L.: Johns Hopkins Hasp. Bull., 32, 10. 1921. 



^ Pringsheim, E. G. : loc. cil. 



'Zukerman, I., and Minkewitsch, I.: Centralbl.f. Bakkriol., I, 80, 483. 1925-26. (Ref.) 



