330 



SPECIFIC MICRO-ORGANISMS 



B. enteritidis groups. They are ordinarily regarded as inter- 

 mediate between B. coli and B. typhosus and are designated 

 as paracolon and paratyphoid bacilli. The diseases in which they 

 occur are sometimes traceable to meat poisoning. B. enteritidis 

 and B. typhi murium doubtless occur in the circulating blood of 

 man at times as paratyphoid bacilli. B. psittasosis is usually 

 regarded as a paracolon bacillus. 



Bacillus Typhosus. Eberth in 1880 and Koch in 1880 ob- 

 served this organism in the spleen and mesenteric lymph glands 



FIG. 133. Bacillus of typhoid fever. X 1000. 



of persons dying of typhoid fever. Gaffky in 1884 obtained the 

 first pure cultures. Metchnikoff 1 and Besredka in 1911 succeeded 

 in causing typical typhoid fever in anthropoid apes (chimpanzees) 

 by feeding them cultures of B. typhosus, thus adding conclusive 

 proof of the causal relationship of this organism to typhoid fever 

 to the abundant strong evidence previously at hand. 



B. typhosus is found in the intestinal contents, mesenteric 

 lymph glands, spleen, blood and urine of patients suffering from 

 typhoid fever. It is 0.5 to o.8/t in width and i to 4/4 in length, 



1 Annals de VInstltut Pasteur, 1911, Vol. XXV, 193-221. 



