320 



TYPHOID FEVER 



just commencing, the spleen, the liver, or a mesenteric gland. 

 The spleen and liver are better than the other tissues named, as 

 in the latter the presence of the b. coli is more frequent. From 

 scrapings of such solid organs dried films may be prepared and 

 stained for a few minutes in the cold by any of the strong 

 staining solutions, e.g. with carbol-thionin-blue, or with Ziehl- 



Neelsen carbol - fuehsin 

 diluted with five parts 

 of distilled water. As a 

 ^ rule decolorising is not 



necessary. For the proper 

 V\ observation of the ar- 

 *A rangement of the bacilli 

 in the tissues, paraffin 

 sections should be pre- 

 pared and stained in 

 carbol-thionin-blue for a 

 fewminutes, orinLofner's 

 methylene-blue for one 

 or two hours. The bacilli 

 take up the stain some- 

 what slowly, and as they 



FIG. 110.-A large clump of typhoid bacilli are also easily decolorised 

 in a spleen. The individual bacilli are the aniline-Oil method ot 

 only seen at the periphery of the mass, dehydration may be used 

 (In this spleen enormous numbers of with advantage (vide p. 

 typhoid bacilli were shown by cultures to g3)> Jn 8uch prepara . 

 be present in a practically pure condition. ) . > r . . 



Paraffin section ; stained with carbol-thionin- tions the characteristic 

 blue, x 500. appearance to be looked 



for is the occurrence of 



groups of bacilli lying between the cells of the tissue (Fig. 110). 

 The individual bacilli are 2 ^ to 4 //, long, with somewhat oval 

 ends, and -5 //. in thickness. Sometimes filaments 8 ^ to 10 ^ 

 long may be observed, though they are less common than in 

 cultures. It is evident that one of the short oval forms may 

 frequently in a section be viewed endwise, in which case the 

 appearance will be circular. This appearance accounts for some, 

 at least, of the coccus-like forms which have been described. 

 The bacilli are decolorised by Gram's method. 



Isolation and Appearances of Cultures. To grow the 

 organism artificially it is best to isolate it from the spleen, as it 

 exists there in greater numbers than in the other solid organs, 

 and may be the sole organism present even some time after 

 death. The spleen is removed whole, and a portion of its 



