CHAPTER VIII. 

 TYPHUS MURIUM. 



BACILLUS TYPHI MURIUM 



General Characteristics. A motile, flagellated, non-sporogenous, 

 non-liquefying, non-chromogenic, aerobic and optionally anaerobic, 

 aerogenic bacillus, pathogenic for mice and other small animals, stain- 

 ing by the ordinary methods, but not by Gram's method. 



Bacillus typhi murium was discovered by Loffler* in 

 1889, when it created havoc among the mice in his labora- 

 tory at Greifswald. 



Morphology. The organism bears a close resemblance 

 to that of typhoid fever, sometimes appearing short, some- 

 times long and flexible. There are many long and curly 

 flagella with peritrichic 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. 



Isolation. The bacilli were first isolated from the blood 

 of dead mice. 



Cultivation. Their cultivation presents no difficulties. 



Colonies. Upon gelatin plates the deep colonies are at 

 first round, slightly granular, transparent, and grayish. 

 Later they become yellowish-brown and granular. Super- 

 ficial 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 grayish-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 de- 

 void 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 reac- 

 tion, without coagulation. 



* "Centralbl. f. Bakt. u. Parasitenk.," xi, p. 129. 

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