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Full text of "Pathogenic Bacteria"




The artificial cultivation which was achieved
Kitasato is not more difficult than that of other
aerobic organisms. In gelatin
containing i to 2 per cent, of
glucose or 5 per cent, of gly-
cerin the organism develops
quite well, the exact appearance
depending somewhat upon the
method by which it was planted.
If the bacteria are dispersed
through the culture-medium,
the little colonies will appear
in the lower parts of the tube as
nearly spherical or slightly irreg-
ular, clouded, liquefied areas con-
taining bubbles of gas. If, on
the other hand, the inoculation
is made by a deep puncture, a
stocking-shaped liquefaction
forms along the whole lower
part of the puncture, leads to
considerable gas-production, and
finally causes the liquefaction of
all the gelatin except a thin
superficial stratum. A peculiar
acid odor is given off by the

When the bacteria grow anaerobically in Esmarch
tubes, the colonies are irregularly club-shaped or spheri-
cal, with a tangled mass of delicate projecting filaments
visible upon microscopic examination.

In agar-agar the development is similar to that in
gelatin. The gas-production is marked, the liquefaction
of course absent, and the same acid odor pronounced.

The bacillus also develops quite well in bouillon, the
bacillary masses sinking to the bottom in the form of
whitish flakes, while the gas-bubbles collect at the top.
In this medium the virulence is unfortunately soon lost

FIG. 129.—Bacillus of symp-
tomatic anthrax: four-days-old
culture in glucose-gelatin (Fran-
kel and Pfeiffer).