TYPHOID BACILLUS .361 
The precautions to be observed are those for any intestinal infection. 
Schmitz Bacillus. Schmitz' and Clarke'' have isolated a bacillus 
culturally quite similar to the Shij?a bacillus, except that it forms 
indol, from dysentery cases in Roumania and Salonica. The organ- 
ism appears to have been somewhat widely distributed in IVIacedonia. 
Serologically, the organism differs from the Shiga bacillus, and from 
the various members of the Flexner group. 
The pathogenesis of the organism is yet to be determined. It has 
been isolated from diarrheal cases of varying degrees of se^'erity. It 
may be identical with B. ambiguus of Andre wes. 
TYPHOID BACILLUS. 
Historical.— Typhoid bacilli were first seen in sections of tissue 
from autopsies by Klebs in 1876. Somewhat later Eberth'' success- 
fully demonstrated them in sections of mesenteric glands, lymph nodes 
and the spleen by the use of the then recently introduced tissue stains. 
GafFky** first isolated the organisms in pure culture and established 
their probable etiological relationship to typhoid fever. Later inves- 
tigations with more refined methods have completely substantiated 
Gaffky's observations. 
Morphology.— Typhoid bacilli are rod-shaped organisms of moderate 
size, measuring from 0.5 to 0.8 microns in diameter and from 1 to 3 
microns in length. The dimensions vary within the limits given upon 
different media, the organisms being, as a rule, somewhat longer in 
fluid media than upon solid media. Elongated rods and even filaments 
are occasionally found in old gelatin and potato cultures. The bacilli 
have rounded ends and occur as a rule singly or in pairs. They are 
actively motile, particularly in young cultures grown in 0.1 per cent 
glucose broth; plain broth cultures are usually more sluggish. Each 
organism possesses characteristically from eight to ten peritrichic 
flagella; rarely as many as twenty may be attached to a single organism. 
The flagella are somewhat wavy in outline and measure from 6 to 8 
microns in length. No spores are produced. It was formerly held 
that typhoid bacilli formed no capsules. Carpano,^ and Gay and 
Claypole,*^ however, have demonstrated capsules arounfl typhoid 
bacilli grown in blood media. 
The organisms stain readily with ordinary anilin dyes and they are 
Gram-negative. 
Isolation and Culture.— The typhoid bacillus grows readily upon the 
ordinary media. Colonies on agar plates are round, colorless, flat and 
nearly transparent; they attain a diameter of from O.f) to 1.5 mm. 
' Miinchen. med. Wchnschr., 1917, 64, 1571. 
- Medical Research Committee Report No. 40, 1919. 
3 Virchow's Arch., 1880, 81, 58; 1881, 83, 4SG. 
' Mitt. a. d. kais. Gesamte, 1884, 2, 870. 
■' Centralbl. f. Bakteriol., orig., 1913, 70, 42. 
'■ Arch. Int. Med.. 1913, 12, 613. 
