Pathogenic Bacteria

SPIRILLA RESEMBLING CHOLERA. 335

medium rich in peptone produces the same rose color
observed in cholera cultivations.

The organism is pathogenic for animals, but not for
man. Pfeiffer has shown that chickens, pigeons, and
guinea-pigs are highly susceptible animals. The birds
when inoculated under the skin generally die—pigeons
always. W. Rindfleish has pointed out that this positive
fatal outcome of the introduction of the spirillum into
pigeons makes it a valuable diagnostic point for the
differentiation of this spirillum from that of cholera.
According to his 'researches, the simple subcutaneous in-
jection of the most virulent cholera cultures is never
fatal to pigeons. The birds only die when the injections
are made into the muscles in such.a manner that the
muscular tissue is injured and becomes a locus minoris
resistentitz. When guinea-pigs are treated according to
the method of Koch for the inoculation of cholera, the
temperature of the animal rises for a short time,, then
abruptly falls to 33° C. or less. Death follows in twenty
to twenty-four hours. A distinct inflammation of the
intestine, with exudate and numerous spirilla, may be
found. The spirilla can also be found in the heart's
blood and in the organs of such guinea-pigs. When the
bacilli are introduced by subcutaneous inoculation, the
autopsy shows a bloody edema and a superficial necrosis
of the tissues.

In the blood and all the organs of pigeons and young
chickens the organisms can be found in such large num-
bers that Pfeiffer has suggested the term " vibrionensep-
ticsemie" for the condition. In the intestines very few
alterations are noticeable, and very few spirilla can be
found.

Gamaleia has shown that pigeons and guinea-pigs can
be made immune by inoculating them with cultures ster-
ilized for a time at a temperature of 100° C. Mice and
rabbits are immune except to very large doses.

Spirillum Berolinensis.—This organism (Fig. 91),
which was discovered by Neisser in the summer of 1893,