GENUS BACILLUS 321 



BACILLUS TYPHOSUS EBEETH. 



Synonyins. Bacillus typhi abdominalis Eberth 1 ; Bacillus, 

 typhosus; bacillus of Eberth ; Eberth- Gaff ky 2 bacillus. 



Place in nature. B. typhosus is the cause of typhoid fever 

 in man) Jt is not demonstrated that it is pathogenic for do- 

 mesticated animals but it is so closely related to certain bac- 

 teria that are of much significance in comparative pathology 

 that it is mentioned here. B. typhosus was discovered by 

 Eberth in 1880 and isolated by Gaffky in 1884. This organism 

 is not known to exist in nature except in the bodies of in- 

 fected people and in water, milk, sewage v etc., contaminated 

 by the infected individuals. It has been clearly demonstrated 

 that this organism remains in the body for a considerable 

 time after recovery. In a few instances they have been found 

 in the feces or urine several years after the patient has recov- 

 ered. Such people are referred to as "bacilli carriers." This 

 condition probably holds in case of the disease caused by B* 

 suipestifer. 



Morphology. B. typhosus is a short rod, from 0.5 to 0.8 /* 

 in width and from 1 to 4 /* in length. Its ends are rounded. 

 It does not produce spores and capsules have not been observed. 

 The flagella appear to be more numerous than in the coli and 

 hog cholera groups. 



Staining 1 . The bacilli stain readily with the usual aniline 

 dyes. They do not take the Gram stain. 



Cultivation. B. typhosus is cultivated without difficulty 

 on the usual culture media. It is not sensitive to the reaction 

 of the media but will grow in media either slightly acid or 

 alkaline. 



Agar. Small grayish colonies at first transparent but 

 later opaque appear on this medium in from 18 to 24 hours. 

 On agar slants the growth is uniform, grayish, with a glisten- 

 ing surface. 



1 Eberth. Virchow's Archiv, Bd. LXXXI (1880) p. 58 and Bd. 

 LXXXIII (1881) p. 489. 



2 Gaffky. Mitt. a. d. Kais. Gesundheitsamt., Bd. II (1884) p. 372. 



