370 THE ALCALIGENES— DYSENTERY— TYPHOID GROUP 
Diagnosis.— The diagnosis of typhoid fever in the living subject may 
be made either by the isolation and identification of the specific organ- 
ism, B. typhosus, or by the demonstration of antibodies specific for 
this organism in the body fluids of the patient. 
(a) Bacteriological Diagnosis. — 1. Isolation of typhoid bacilli 
from the blood stream and from rose spots. 
Typhoid bacilli are found in the peripheral blood of a large percen- 
age of typical cases of typhoid fever during the latter part of the 
incubation period. The organisms are found less frequently in the 
later stages. The statistics reported by Coleman and Buxton,^ 
covering 1137 cases, show this clearly. 
Positive 
Cases. per cent. 
First week of clinical disease 224 89 
Second week of clinical disease 484 73 
Third week of clinical disease 268 60 
Fourth week of clinical disease 103 38 
Fifth week of clinical disease 58 26 
The organisms have also been isolated from rose spots (which 
appear, as a rule, early in the clinical course of the disease) by Richard- 
son and others. From these observations typhoid fever may be 
regarded primarily as a bacteriemia.- It should be remembered, how- 
ever, that the organisms are destroyed in the blood stream by specific 
lysins, and that their presence in the circulating fluids of the body 
is partly caused by an overflow of organisms from foci in the spleen 
and other organisms. 
Method of Collecting Blood.— The skin of the elbow is thoroughly 
cleansed as for a surgical operation, a tourniquet is applied, and a 
large hypodermic needle is introduced into a vein, preferably the 
median basilic. From 5 to 15 cc. of blood are removed, discharged 
at once into a flask containing 150 to 250 cc. of glucose broth (0.1 
per cent), and mixed thoroughly before clotting takes place. This 
considerable dilution of the blood is important, partly because clotting 
takes place more slowly and thus fa^•ors the escape of the organisms 
into the broth, and also because it dilutes the lysins which are usually 
present in the blood of typhoid patients. It is necessary to reduce 
the concentration of lysins, for lysins dissolve typhoid bacilli. Incu- 
bation of the culture at 37° C. for twenty-four hours usually results 
in a growth of bacteria in which the specific organisms are present, 
either alone or mixed with skin cocci. 
Coleman and Buxton^ recommended an ox-bile glycerin peptone 
medium for the isolation of typhoid bacilli. The medium as prepared 
by them has the following composition: Ox-bile, 900 cc. ; glycerin, 
100 cc; peptone, 20 grams. This is sterilized in the autoclave and 
1 Am. Jour. Med. Sci., 1907, 123, 896. 
2 Brion and Kayser: Deutsch. Arch. f. klin. Med., 1906, 85, 552. Coleman and 
Buxton: Jour. Med. Res., 1909, 21, 83. KoUe and Hetsch: Experimentelle Bakteriol. 
und Infektionskrankh., 1911, 3 ed., 1, 250. 
3 Loc. cit. 
