456 A MANUAL OF BACTERIOLOGY 



bacilli. The former is culturally like B. shigw> except that it 

 forms indole and is inagglutinable with Shiga serum. Gettings' 

 bacillus is culturally identical with the Flexner bacillus, but is 

 inagglutinable with Flexner serum of any type. 



Spirobacillus zeylanicus is an organism described by Castellani 

 and occurring in diarrhoeic and dysenteric stools. It is charac- 

 terised by extreme pleomorphism, appearing as bacillar, vibrio -like, 

 spirillar and pseudo-spirillar forms. It is Gram -negative and 

 motile and grows on agar as a greyish film, not unlike the growth 

 of B. dy sentence. On gelatin it forms a whitish film without 

 liquefaction, and on potato a brownish-red growth, somewhat 

 like that of B. mallei on this medium. Milk is rendered alkaline 

 and not clotted. Neither acid nor gas formation occurs with 

 fermentable substances, but an alkaline reaction usually develops. 

 The colonies on Conradi. Endo and MacConkey agar media are 

 much like those of the dysentery -typhoid group. It is non- 

 pathogenic to animals and probably non -pathogenic to man. 1 



Clinical Diagnosis 



1. Agglutination. The patient's serum may be examined for 

 agglutination against the Shiga and the Flexner strains by the 

 methods given on p. 430. Cultures for the " Standard " method 

 are supplied by the Oxford laboratory ; the mixtures should be 

 heated at 55 C. for four hours. 



2. Examination of the Fceces. This may be carried out by the 

 method given on p. 438; the material should be fresh. Rajchman 

 and Western's method (loc. cit. ) is as follows : 



Dilutions (p. 438) are plated on litmus lactose agar and incubated 

 overnight at 37 C. Suspicious blue colonies are then picked out 

 and sub -cultured on sloped agar tubes ; not less than three 

 colonies should be sub-cultured. Experience will decide what 

 blue colonies to select ; some blue colonies may be alkali-producers 

 and not simply non-lactose ferrnenters which often give at this 

 stage colourless or pale colonies. The general appearance, 

 structure and consistency of the colonies are important characters, 

 as well as the colour. 



1 See Frank Taylor, Journ. Pathol. and Bacteriology, vol. xxii, 1919, 

 p. 262. 



