A NEW PATHOGENIC BACILLUS 
405 
Summary 
1. Intermediate between B. typhosus and B. coli are a number of organisms 
whose cultural characteristics are so constant (chief among them 
being their power of fermenting glucose but not lactose, combined 
with an inability to clot milk), that they may well be classified together 
as forming the B. enteritidis group. 
2. The fourteen cases hitherto reported, of fever clinically like typhoid, 
whose bacteriology and serum-reactions show that they were not 
caused by B. typhosus, have been practically all caused by members 
of the B. enteritidis group. 
3. The present report adds another case to this series ; the aetiological 
organism, Bacillus C L,' being very closely related to the B. enteri- 
tidis group. 
4. A study of the cultural features of this group shows the importance of 
(a ) recording the action of a given organism in lactose as well as 
in glucose media ; (b ) observing milk cultures over an extended 
period of time, not less than two weeks. 
5. The Neutral-red reaction in glucose media cannot be regarded as 
characteristic of B. coli, but is readily given by the members of the 
B. enteritidis group, organisms capable of producing an infection 
like typhoid fever. 
6. A negative serum-reaction in cases clinically diagnosed as typhoid, 
rather than lowering the value of serum diagnosis, may have an 
important bearing on our knowledge of the aetiology of typhoid 
fever. 
7. In cases, apparently typhoid, which give a negative serum-reaction with 
B. typhosus, the agglutination-test should also be made with 
available organisms of the B. enteritidis group. 
In conclusion, the writer desires to express his thanks to Dr. A. S. Grilnbaum 
for constant guidance during the study, and for many suggestions which have been 
followed in the work ; also to Dr. Caton for his kind permission to report the case ; 
and to Dr. Frederick Griffith, House Physician in the Royal Infirmary, for much 
assistance in procuring specimens for bacteriological study. 
z 
