516 Bacilli Resembling the Typhoid Bacillus 



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. 



(6) The Pneumonic or Psittacosis Group. Psittacosis is 

 an epidemic infectious disease with pneumonic symptoms 

 and a high mortality. Its origin has been traced to dis- 

 eased 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 agglutinate with typhoid serums. 



It is thus evident that some of the intermediates occasion 

 symptoms 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,* and Johnson, Hewlett, 

 and Longcope f have studied the paratyphoid infections, 

 Gwyn,J Libman, and others the paracolon bacilli, and 

 Gushing || and Durham ** 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 organisms 

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

 attention will be devoted only to the more important 

 organisms of the group and to a few belonging to offshoots 

 from the parent stem Bacillus dysenteriae, Bacillus faecalis 

 alkaligenes, and Bacillus psittacosis. 



* "Soc. Med.," Nov., 1896. 



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



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



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



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



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



