160 



BACILLUS TYPHI ABDOMINALIS. 



Eberth(lS80). 



BACILLUS OF TYPHOID FEVER J KOCII-EBERTIl's BACILLUF. 



Origin. First obtained from the spleen and lymphatic glands 

 of typhoid fever cadavers; present in the blood, in 'small numbers, 

 and in the feces of typhoid patients. 



Form. Well formed rods, 3-5 times as long as wide, with 

 rounded ends. The length varies greatly with the nature of the 

 medium on which it grows. Thus on agar it forms very short rods, 

 while on potatoes it may grow into long threads. Involution forms. 



Motility. Is very actively motile. Has numerous lateral 

 whips. 



Sporulation. Terminal, round or oval bodies are found in 

 potato and agar cultures which are grown in the incubator for sev- 

 eral days. They do not double stain and the bacilli containing 

 these are very susceptible to heat. They are not therefore true 

 spores. The bacilli are very resistant to desiccation and may retain 

 vitality for months. 



Anilin Dyes. Does not stain as well with ordinary anilin 

 dyes as most bacteria; carbolic-fuchsine stains excellently. Does 

 not stain by Gram's method. 



Growth. Is rather rapid, In its cultural properties it greatly 

 resembles the two preceding organisms. 



Ptdfcx. The deep co'onies on gelatin plates are small, round, sharply 

 bordered, finely granular and yellowish. Th- surface colonies spread freely 

 as an almost transparent film, which has an irregular, wavy horder, and is 

 delicately marked with branching lines. No liquefaction. 



Stich< ullun'x Abundant growth along tn<> entire line of inoculation, 

 and especially so on i he surface wh^re it spreads as a thin, grayish white 

 covering. Gelatin eventually becomes cloudy, due to the production of acids. 



Streak Cnttui'm. Jn ut/nr and on hi >')<! serutn, forms moist, white 

 growth, without any special characteristics. On potatoes, as a rule, the growth 

 is very characteristic. It covers the surface as a moist, invisible layer -dis- 

 tinction from preceding organisms. On alkaline potatoes the growth is yel- 

 lowish and no longer characteristic. 



Oxygen requirements. Is a facultative anaerobe. 



Temperature Grows well at ordinary temperature. The 

 optimum is about 37 C. Is quicklv killed by even short exposures 

 to heat of 60. 



Behavior to Gelatin. Does not liquefy. 



Pathogenesis. Intravenous injections usually kill rabbits. 

 Is usually fatal to guinea-pigs, when introduced into the previously 

 alkalinized stomach, or when injected into the duodenum. Intoxi- 

 cation. This bacillus is generally accepted as the cause of typhoid 

 fever. 



Infection. Commonly takes place through the mouth by 

 means of water, food, contact with soiled articles, etc. In later 

 stages other organisms as streptococci frequently appear "mixed 

 infection." 



NOTE. Make Esmarch potato cultures of the Eberth, coli communis, 

 and Emmerich bacilli; place in the incubator for 2-8 days. Carefully compare 

 these as well as the cultures on other media, etc. Make impression prepara- 

 tions of colonies. 



