BACILLUS OF TYPHOID FEVE& 427 



teria were used, protection was only slight. Better results were ob- 

 tained that is, apparently complete protection within 8 to 10 days 

 when living sensitized bacteria were injected. (Bacteria which had 

 been exposed to the action of inactivated immune serum.) Brough- 

 ton 1 has applied this method to human beings. Gay 2 has also pre- 

 pared a sensitized dead typhoid vaccine which he has already used in 

 a considerable number of cases. It will take some time, however, before 

 a statistical estimation of the superiority of this method over the older 

 vaccination with dead bacteria will be possible. 



Attempts have recently been made to treat active typhoid fever by 

 intravenous injections of sensitized vaccines. The cases are as yet too 

 few to permit final judgment. 



BACILLUS FECALIS AI KALIGENES 



In 1896 Petruschky 3 described a bacillus which is a not infrequent 

 inhabitant of the human intestine, being found chiefly in the lower 

 part of the small intestine and the large intestine. This organism, 

 which he called Bacillus fecalis alkaligenes, is of little pathogenic im- 

 portance, although Neufeld states that he has seen a case of severe 

 gastroenteritis in which the watery defecations contained this bacillus 

 in almost pure culture. As a rule, however, this organism cannot be 

 regarded as pathogenic, and is important chiefly because of the ease 

 with which it may be mistaken for Bacillus typhosus. 



Bacillus fecalis alkaligenes is an actively motile, Gram-negative 

 bacillus, ' possessing, like the typhoid bacillus, numerous peritrichal 

 flagella. On the ordinary culture media it grows like the typhoid 

 bacillus. It does not coagulate milk. It produces no indol, and on 

 sugar media in fermentation tubes produces no acid or gas. On 

 potato, its growth, while somewhat heavier than that of the typhoid 

 bacillus, is not sufficiently so to permit easy differentiation. It differs 

 from Bacillus typhosus in that it produces no acid on any of the sugar 

 media, and is therefore easily differentiated by cultivation upon Hiss 

 serum-water media or on pepton waters containing sugars. On the 

 Hiss semi-solid tube-medium Bacillus fecalis alkaligenes, while cloud- 

 ing the medium throughout, grows most heavily on the surface, where, 

 eventually, it forms a pellicle. 



1 Broughton, C. R. de TAcad. des Sc., cliv, 1911. 



2 Gay, Arch, of Int. Med., 1914. 



Petruschky, Cent, f . Bakt., I, xix, 1896- 



