PARATYPHOID GROUP 205 



explained either on the ground of their group relationship or the 

 absorption of the toxic substances of the organism through the 

 diseased intestinal mucous membranes. 



Vaccines. Vaccines have been found beneficial in cases of 

 cystitis and appendicitis due to the colon bacillus. The dose 

 ranges from 25 to 500 million organisms. 



B. Coli Communior. The organism is probably as abundant 

 in the intestinal tract as B. coli communis itself. Morphologically 

 and culturally they are identical, save that the latter does not 

 ferment saccharose, whereas B. coli communior is able to form 

 both acid and gas from it. 



Capsulated Bacilli. Closely related to the colon bacilli, and 

 by some authorities included with them, are a number of organ- 

 isms which differ from the latter in that they are non-motile and 

 that they are usually heavily capsulated. Of these B. lactis 

 aerogenes is perhaps the most frequently met with. It is normally 

 present in the intestines, in sewage, and in water. It is almost 

 always present in milk and cream and is one of the principal agents 

 causing them to become sour. Another of the capsulated bacilli, 

 B. pneumonia or Friedlander's pneumobacillus, isolated by Fried- 

 lander in 1882, was regarded for a time as the cause of lobar 

 pneumonia. More recent discoveries have proved, however, 

 that the pneumococcus is responsible for the vast majority of 

 the cases of the disease. The type of pneumonia caused by 

 Friedlander's bacillus is relatively infrequent and has a very 

 high mortality. Still other members of the capsulated group are 

 B. ozence the causal agent of fetid rhinitis, and B. of rhinoscleroma, 

 which receives its name from the disease it gives rise to. 



PARATYPHOID GROUP 



Between the colon and typhoid bacilli are a large number 

 of organisms which possess the common group characteristics, 

 i.e. they do not liquefy gelatin, are Gram negative, and do not 

 form spores, yet they show wide variations in their reaction on 

 sugars and are not agglutinated by either typhoid or coli immune 

 serum. Near the typhoid end of the scale organisms exist which 



