COLON BACILLUS' TFST; - IOI 



SOLUTION No. I 



Para-dimethyl-amido-benzaldehyde 4 parts 



Absolute alcohol 380 parts 



Concentrated HC1 80 parts 



SOLUTION No. II 

 Sat. sol. of potassium persulphate. 



The indol test is performed as follows : Add 5 cc. of solution I 

 to 10 cc. of a broth culture and then add 5 cc. of solution II, the 



rr 



v 



FIG. 28. Bacillus of typhoid fever, stained by Loeffler's method to show flagella 



(X 1000). (Williams.} 



whole being then shaken. A red color indicates indol. Some of 

 the leading bacteriologists consider this a very valuable test. 



The so-called hog cholera group or the Gaertner group of bacilli 

 is important from the standpoint of the food bacteriologist. The 

 Gaertner group occupy a position intermediate between the 

 chemically active coli group and the chemically inert typhoid 

 group and includes the following important species or rather strains 

 the Bacillus enteritidis strain which includes many of the bacteria 

 isolated in cases of food poisoning and some of the B. typhi murium 



