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STUDIES ON SALMONELLA GALLINARUM [Vol. XXII, Part III,
the two organisms and, while recognising their similarity as regards their antigenic
structure, noted the difference in the carbohydrate fermentation, such as gas produc-
tion by S. pullorum and fermentation of maltose by S. gallinarum. Hadley et al.
[1917] reported infection in adult fowl due to non-gas producing type of pullorum.
The gas producing type has come to be known as S. pullorum 'A' and non-gas
producing type as S. pullorum 'B' Muslow [1919] found that certain strains
of S. pullorum fermented maltose and hence suggested dulcitol as a better differen-
tiating sugar. Hendrickson [1927] concurred with Muslow in using serum water
as a basic medium for sugars. He attributed Maltose fermentation by S. pullorum
to the materials and methods employed for the cultivation of the organism and
suggested peptone water instead. He considered S. gallinarum as maltose, dulcite
and dextrain positive. Van Roekel [1937] isolated strains of S. pullorum which
fermented maltose within a few hours. Hinshaw [1941] showed by fermentation
of carbohydrates that there were several sub-species in S. pullorum and S. gallinarum
groups, like S. pullorum intermediate, type 'A', which produced acid and gas in
maltose, dulcite and arabinose, and S. pullorum intermediate 'B' which produced
acid only in maltose, dulcite and arabinose, but none of the two fermented xylose
in addition, like S. gallinarum.
Experimental work
Epidemiology. In the beginning of 1950 an acute outbreak of fowl typhoid
occurred in a large poultry farm. First the adults and later the baby chicks were
affected perhaps in consequence of hatching from the carriers. This made a study
of its various aspects possible for the first time in India. The disease spread rapidly
into the majority of the breeding pens. The birds in full lay were found droopy
ruffle feathered, off feed and reluctant to move. Some had matted fluff due to
greenish diarrhoea which developed in birds that lingered on for a few days. The
temperature was 1° to 3° F. above normal, comb and wattles became cyanotic and
death supervened after a couple of days of ailment (Plate XI. fig. 1.)
The early cases were peracute for the first two weeks and later the rate of
mortality decreased and the coarse also became protracted, the symptoms being-
pallor of the comb and wattels and profuse green diarrhoea. Pending diagnosis,
the spread of the disease was checked by depopulation of the visibly affected birds
and sanitation. The probability of food poisoning was eliminated by biological
and cultural tests.
Post-mortem findings. Over a hundred birds were autopsied. No special
lesions were noticed in peracute cases and the blood was negative under the micros-
cope for organisms. In cases of delayed mortality a common though not constant
lesions was a linear band of haemorrhage varying from 2 to 3 m.m. in width n the
sub-mucosa of the proventriculus near the gizzard-end. Occasionally there were
necrotic ulcers in the horny epithelium of the gizzard. Liver was enlarged and
friable containing numerous yellow or grey necrotic foci, almost similar to the lesion
seen in diffuse lymphomatosis. Pericardium showed serofibrinous adhesion and
in the heart wall large necrotic foci as big as the seeds of garden peas were observed.
The spleen was enlarged being more than thrice the normal size with numerous small
areas of necrosis, or at times studied with multiple nodules. Acute cases showed
a severe haemorrhagic follicular enteritis, while in more prolonged cases circular