SEPTEMBER, 1948]
JOHN
B.
POLDING
185
they have been very scantily examined. Again, on account of the extreme difficulty of obtaining
pregnant goats for animal-inoculations and of preventing the few obtained from dying of pneumonia
in the rigours of the Kumaun winter, the results of animal passage are too few to be convincing, For
what they are worth, however, they are very briefly appended.
The organism is a small gram-positive cocco-bacillus or bacillus, reminiscent of the short form of Lis-
terella, but, unlike Listerella, long forms have not yet been observed and pleomorphism is slight. The
organism is believed to be sluggishly motile, but growth is so feeble at bench temperatures that ins-
pection during the first 72 hours is almost fruitless. Spores are not formed. Growth at 37°C is
almost equally problematical in broth or on agar and unless strains are passaged every three days they
will sooner or later be lost. ACO 2 atmosphere does not improve matters. Comparative growth has
been observed on 2 per cent tryptose agar, liver agar, and 1 per cent glucose agar and in 2 per cent
tryptose and 2 per cent, 1 per cent and 0.5 per cent glucose broth. One per cent glucose seems to
be very much better than other concentrations while 2 per cent tryptose is a very good substitute.
On solid media, colonies are pin-point to small pin-head, translucent, sparkling and beadlike. They
neither enlarge with time nor tend to coalesce. So far, isolation cultures have shown sparce colony
growth only. The continuous growth, seen on established cultures, is so faint as to be only discernable
by the closest scrutiny, while manipulating the slant in transmitted light. For a day or two, it appears
as little more than a faint fogging on the surface of the agar, which may be confused with a patch of
dried condensation. This wraith-like appearance on solid media is characteristic and although well-
established strains occasionally get slightly denser, as a rule, the culture dies before it can thicken.
The growth in broth produces a uniform faint turbidity, part of which, in well established cultures,
deposits in the form of light flakes.
On none of the media used, can growth be expected before the second or third day of incubation
and even well adapted strains may fail to emerge before the fourth. At any time a strain may
die for no apparent reason and to obviate this mishap it is desirable to maintain cultures in 2 per cent
tryptose or 1 per cent glucose broth and to subculture twice weekly by pipetting a substantial quantity
from the old to the new tube. Before this system was developed several promising lines—X31
amongst them were lost, and at one time it was thought impossible to maintain even a single example.
Table (XLV) gives the results of the usual biological tests, which were compared with Miss Bar-
ber's [1939] findings for Listerella. On the whole, there is considerable dissimilarity and to clinch
matters, cross agglutination with Listerella does not occur.
TABLE XLV
The biological reactions of X strains
—
Glucose . . . . . . . . . . .
Inulin . . . . . . . . . . .
Maltose . . . . . . . . . . .
Raffinose . . . . . . . . . . .
Salicin . . . . . . . . . . .
Lactose . . . . . . . . . . .
Mannite . . . . . . . . . . .
Rhamoose . . . . . . . . . . .
Sorbite . . . . . . . . . . .
Dextrol . . . . . . . . . . .
Sucrose . . . . . . . . . . .
Trehalose . . . . . . . . . . .
Gelatin . . . . . . . . . . .
H 2 S . . . . . . . . . . .
Nitrates . . . . . . . . . . .
V. P. . . . . . . . . . . .
Methyl Red . . . . . . . . . . .
Indol . . . . . . . . . . .
Litmus milk . . . . . . . . . .
Listerella
+
—
+
—
—
± late
—
+
—
+
± late
+
—
—
0
+ weak
×
—
+ trace
X 31
+
0
—
0
—
± late
0
—
—
+
+
± late
—
—
—
—
—
—
—
X 39
+
—
—
+
+
± late
—
—
—
+
+
+
—
0
—
—
—
—
—
+=Acid, no gas.
—=No acid, no gas.
0=test not done.