CHAPTER X 



TYPHOID FEVER - - PARATYPHOID FEVER - - BACILLUS 

 ENTERITIDIS AND THE GARTNER GROUP SWINE FEVER 

 BACILLUS DYSENTERIC BACILLUS COLI 



THE organisms considered in this chapter form a natural group 

 known as the " Typhoid-Colon " group. They are for the most 

 part primarily inhabitants of the intestinal tract of man and 

 animals, though many of them are capable of a saprophytic 

 existence, at least for a time. They are all Gram -negative, non- 

 sporers, and, with few exceptions, non-liquefiers of gelatin. The 

 subdivisions of the Typhoid-Colon group are largely based upon 

 fermentation reactions, and the individual members in some cases 

 are likewise distinguishable by fermentation reactions ; in others 

 the finer serolpgical reactions are necessary for differentiation. 

 The classification of the Typhoid-Colon group has been attempted 

 by Loffler, Henderson-Smith, Chalmers and Macdonald (Lancet, 

 1916, vol. ii, p. 139), and Chalmers and Castellani (Ann. de VInst. 

 Pasteur, vol. xxxiv, p. 600), among others. Winslow, Klizler 

 and Kothberg (Journ. Bacteriology, vol. iv, 1919, p. 429) have 

 made a careful study of the group, and the following is a summary 

 of their classification : 



The group may be divided into two primary subdivisions by 

 the presence or absence of the power to ferment lactose. The 

 lactose fermenters are generally of more vigorous growth, though 

 less actively motile, are more vigorous in their attack on other 

 carbohydrates, and are indole producers. They are as a rule of low 

 pathogenic power. 



The non -lactose fermenters are divisible into four groups : 



Group I includes the forms of low fermentive power, capable 

 of attacking only the simplest hexoses if they ferment at 

 all. This group contains B. alkaligenes and Shiga's 

 dysentery bacillus (termed B. shigce). 



