Bacilli Resembling the Typhoid Bacillus 



629 



Morphology. — The organism bears a close resemblance to that of typhoid fever, 

 sometimes appearing short, sometimes long and flexible. There are many long 

 and curly flagella with peritrichial arrangement, and the organism is actively 

 motile. It does not produce spores. 



Staining. — It stains with the ordinary dyes, but rather better with Loffler's 

 alkaline methylene blue, not by Gram's method. 



Isolation. — The bacilli were first isolated from the blood of dead mice. 



Cultivation. — Their cultivation presents no difi&culties. 



Colonies. — Upon gelatin plates the deep colonies are at first round, slightly 

 granular, transparent, and grayish. Later they become yellowish brown and 

 granular. Superficial colonies are similar to those of the typhoid bacillus. 



Gelatin. — In gelatin punctures there is no liquefaction. The growth takes 

 place principally upon the surface, where a grajash-white mass slowly forms, and 

 together with the growth in the puncture suggests a large flat-headed nail. 



Agar-agar. — Upon agar-agar a grayish-white growth devoid of peculiarities 

 occurs. 



Potato. — Upon potato a rather thin whitish growth may be observed after a 

 few days. 



Milk. — The bacillus grows well in milk, causing acid reaction, without coagu- 

 lation. 



Fig. 257. — Bacillus typhi murium (Migula). 



Bouillon. — In bouillon it produces clouding. There is no fermentation of 

 saccharose, dextrose, lactose, or levulose. 



Pathogenesis. — The organism is pathogenic for mice of all kinds, which suc- 

 cumb in from one to two days when inoculated subcutaneously, and in from eight 

 to twelve days when fed upon material containing the bacillus. The bacilli 

 multiply rapidly in the blood- and lymph-channels, and cause death from 

 septicemia. ■ 



Loffler expressed the opinion that this bacillus might be of use in ridding 

 infested premises of mice, and its use for this purpose has been satisfactory in 

 many places. He has succeeded in ridding fields so infested with mice as to be 

 useless for agricultural purposes, by saturating bread with bouillon cultures of the 

 bacillus and distributing it near their holes. The bacilli not only killed the mice 

 that had eaten the bread, but also infected others that ate their dead bodies, the 

 extermination progressing until scarcely a mouse remained. 



In discussing the practical employment of this bacillus for the satisfactory de- 

 struction of field-mice, Brunner* calls attention to certain conditions that are 

 requisite: (i) It is necessary, first of all, to attack extensive areas of the invaded 

 territory, and not to attempt to destroy the mice of a small field into which an 

 * "Centralbl. f. Bakt.," etc., Jan. 19, 1898, Bd. xxiii, No. 2, p. 68. 



