BACILLI OF THE COLON-TYPHOID-DYSENTERY GROUP 691 



B. enter! ti dis group, in other words, the meat poisoning group of 

 man, is culturally indistinguishable from other paratyphoid "B" 

 organisms, but represents a distinctive agglutinative group, at least in 

 the strains obtained by him. 



Jordan adds in his last paper of 1920 that there is no escape from 

 the conclusion that variations are common in the paratyphoid-enter- 

 itidis group, both as to fermentation and agglutination. He sum- 

 marizes that the most permanent characteristics of the group are the 

 fact that rhamnose is fermented by all the paratyphoids, but is not 

 fermented by typhoid; that paratyphoid "A" neglects to ferment 

 xylose, whereas all the other members of the group do ferment xylose. 

 Added to this is the fundamental ability of the group as a whole, includ- 

 ing the typhoid bacilli, to attack glucose. These fermentation charac- 

 teristics are fundamental, are the least subject to change, and, according 

 to Jordan, are more basically characteristic than are the agglutinative 

 reactions, 



PATHOGENICITY OF THE PARATYPHOID GROUP FOR 



ANIMALS 



We have already seen that organisms of this group cause a con- 

 siderable number of different animal disease. 



B. HOG CHOLERA. It was formerly believed that hog cholera was 

 due to the bacillus which bears this name, and first described in this con- 

 nection by Salmon and Smith, 27 but since then it has been found that 

 this disease is due to a filtrable virus. The constant presence of the 

 organism in animals suffering from this disease, is, therefore, something 

 of a mystery, but is probably due, as Dorset has suggested, to the fact 

 that the organism is a constant inhabitant of the intestinal canal in 

 hogs, and manages to get into the circulation as a consequence of the 

 pathological conditions incident to hog cholera. It is worth noting 

 that a similar association of organisms in blood cultures, etc., with dis- 

 eases of which thejr are obviously not the primary etiological factor 

 has been observed in other conditions, notably, for example, the Plotz 

 bacillus in typhus fever. 



B. TYPHI MURIUM. In rodents diseases caused by the members of 

 the paratyphoid group are common. We have already spoken of 

 Loeffler's discovery of the B. Typhi Murium as the cause of an epidemic 

 disease of mice, a condition which is of the greatest annoyance to 

 breeders of mice for cancer research and other laboratory purposes. 



27 Salmon and Smith, Rep. of Com. of Agri., Wash., 1885 and 1886. 



