Pathogenic Bacteria

BACILLUS CO LI CO MM UN IS. 393

tions connected with the intestines, as, for example,
appendicitis.

It is a question whether the colon bacillus is always
virulent, or whether it becomes virulent under abnormal
conditions. Klencki1 found that it was very virulent in
the ileum, and less so in the colon and jejunum, espe-
cially in dogs. He also found that the virulence was
greatly increased in a strangulated portion of intestine.
Other observers, as Dreyfuss, found that the colon bacil-
lus as it occurs in normal feces is non-pathogenic. Most
experimenters, however, believe that pathological con-
ditions, such as disease of the intestine, ligation of the
intestine, etc., cause increased virulence.

Adelaide Ward Peckhatn, in an elaborate study of the
" Influence of Environment on the Colon Bacillus,"2 con-
cludes that while the conditions of nutrition and develop-
ment in the intestine seem to be most favorable, the colon
bacillus is ordinarily not virulent, because uits first force
is spent upon the process of fermentation, and as long as
opportunities exist for the exercise of this function the
affinities of this organism appear to be strongest in this
direction.

" Moreover, the contents of the intestine remain acid
until they reach the neighborhood of the colon, and by
that time the tryptic peptons have been formed and
absorbed to a great extent.

" During the process of inflammation in the digestive
tract a very different condition may exist. The peptic and
tryptic enzymes may be partially suppressed. Fermenta-
tion of carbohydrates and proteid foods then begins in
the stomach, and continues after the mass of food is
passed on into the intestine. The colon bacillus cannot,
therefore, spend its force upon fermentation of sugars,
because they are already broken up and an alkaline fer-
mentation of the proteids is in progress. It also cannot
form peptons from the original proteids, for it does not

1 Ann. de rinst. Pasteur, 1895, No. 9.

2 Journal of Experimental Medicine, Sept., 1897, vol. ii., No. 4, P- 549-