VARIATION OF SALMONELLA PULLORUM 31 



Behavior in Saline Solution 



The property of auto-flocculation or agglutination of cultures was first reported 

 by Nicolle, Steinhardt, Savage, and others. This phenomenon was looked upon 

 as being similar to the agglutination reaction which occurs between a saline 

 emulsion of cells and agglutinating serum. Furthermore, it was claimed that the 

 end result in the two phenomena cannot be differentiated. This statement cannot 

 be applied to the reaction of all 5. pulloriim variants, since the type of reaction 

 can readily be distinguished from the true typical agglutination in the majority 

 of cases. It is also recognized by some investigators that the so-called true "R" 

 variant is characterized by its instability in saline solution. In order to determine 

 whether this applies also to 5. pullorum variants, the various types that have 

 been isolated were placed in different concentrations of NaCl solution. The sus- 

 pensions were prepared from cultures incubated at 37° C. for 48 hours. Table 6 

 shows the reactions of different variants. The results in this table reveal that 

 different types of variants may exhibit the same type and degree of reaction. 

 For instance, Variants D-l, D-2, IV-a, IV-b, V-a, X-a, and Xll-a do not exhibit so 

 much settling as do some other variants which are characterized by a colony form 

 that is more remote from the normal type. However, some very rough colony types 

 do appear more stable in saline solution than variants that are less rough in 

 nature. The precipitate in some cases may be organized in clumps, and in others 

 it may be re-suspended in a homogeneous emulsion. The extremely rough colonies 

 developing on plain agar are characterized by their brittleness, which thus far 

 has made it impossible to produce a uniform homogeneous suspension. Grinding 

 of such cultures in a mortar greatly reduces the size of the clumps, but does not 

 prevent the cells from settling. The rough variants on liver infusion agar produce 

 a suspension in saline solution which is practically free from clumps which are 

 visible to the naked eye. The process of settling may occur within a few minutes 

 after the cells are suspended in the salt. The degree of clearing may be as complete 

 as in true "four plus" agglutination. Partial or complete clearing may baffle one 

 in the routine testing of fowl for pullorum disease, especially when slight clumping 

 is also present. Such a reaction may in certain respects resemble that of a doubtful 

 or non-specific reacting bird. Hence it appears that strains employed for the 

 preparation of antigen which is to be used for serological purposes may cause 

 considerable trouble if their stability in salt solution is decreased through certain 

 environmental influences. 



Behavior in Fermentable Substances 



In this experiment an effort was made to determine the ability of variants to 

 attack different fermentable substances, and to observe the character of growth. 

 The different variants (A, A-l, B, B-l, C, D-l, D-2, E, I-a, Il-a, lib, Ill-a, IV-a, 

 IV-b, V-a,VI-a, VHI-a, IX-a, IX-b, X-a X-c, Xll-a, XH-b, XHI-a, XV-a, XVI-a, 

 XVIII-a) were tested in the following fermentable substances: Arabinose, dextrine, 

 dextrose, dulcitol, galactose, inositol, inulin, lactose, levulose, maltose, mannitol, 

 rafhnose, rhamnose, salacin, sucrose and xylose. It may be stated that the variants 

 attacked the same carbohydrates as did the typical S. pullorum strains or types. 

 However, retarded growth and delayed fermentation were exhibited by some vari- 

 ants, particularly variants B and B-l. Levulose was not attacked by all of the 

 variants, and most strains which acted upon it showed late acid production. Few 

 produced gas with this carbohydrate. Some strains exhibited a settling of cells 

 and clearing of the supernatant fluid, which was especially true when acid produc- 



