,6i4 Bacilli Resembling the Typhoid Bacillus 



The characteristics of the three groups as shown by the fermenta- 

 tion-test stand thus:* 



Gas upon Gas upon Gas upon 



dextrose. lactose. saccharose. 



Bacillus typhosus — — — 



Intermediates + — — 



Bacillus coli communis + + — 



Bacillus coli communior -|- H- -|- 



Buxton finds those pathogenic for man clinically divisible into 

 three groups, as follows: 



(a) The Meat-poisoning Group. — This includes Bacillus enteritidis 

 of Gartner and others. The symptoms begin soon after eating the 

 poisonous meat, and are toxic. Bacilli quickly invade the body. 

 The illness continues four or five days, after which recovery is quick. 

 In a few cases death has occurred on the second or third day. 



(b) The Pneumonic or Psittacosis Group. — Psittacosis is an epi- 

 demic infectious disease with pneumonic symptoms and a high 

 mortality. Its origin has been traced to diseased parrots, and from 

 them Nocard isolated Bacillus psittacosis, supposed to be the cause 

 of the disease in man. Later epidemics were studied by Achard 

 and Bensaude. 



(c) The Typhoidal Group. — The organisms to be included in this 

 group occasion symptoms closely resembling typhoid fever, though 

 they differ biologically from the typhoid bacillus, and do not agglu- 

 tinate with typhoid serums. 



It is thus evident that some of the intermediates occasion symp- 

 toms resembling typhoid fever, while others occasion symptoms 

 widely differing from it. It is suggested that to the former the 

 term paratyphoid bacilli be applied, while the latter are known as 

 paracolon bacilli. 



Although Achard and Bensaude,t and Johnson, Hewlett, and 

 LongcopeJ have studied the paratyphoid infections, Gwyn,§ Lib- 

 man,|| and others the paracolon bacilli, and Gushing** and Durhamft 

 have made comparative studies of the members of the group, it is 

 still too soon to regard the knowledge attained sufficient to warrant 

 particular mention of the various intermediate and related organ- 

 isms in a work of this kind. In the following pages, therefore, 

 attention will be devoted only to the more important organisms of 

 the group. 



* Hiss and Zinsser, "Text-book of Bacteriology," loio, p. 420. 



t"Soc. Med.," Nov., 1896. 



t"Amer. Jour. Med. Sci.," Aug., 1902. 



§ "Johns Hopkins Bulletin," 1898, vol. ix. 



II "Journal of Medical Research," 1902, p. 168. 

 ** "Johns Hopkins Bulletin," 1900, vol. xi. 

 tt" Journal of Experimental Medicine," 1901, vol. v, p. 353. 



