September, 1958] S. S. KHERA AND M. R. DHANDA 121
were picked up and transferred to a suitable medium with a view to obtaining pure
cultures for further study. In some cases where there were more than one type of
colonies on the plate as judged by the naked eye and by means of a hand lens, a
single colony of each type was picked up.
Isolation of Salmonella cultures from faeces
For most of the cases, the material from the stomach and the intestines was
dealt with mainly for the isolation of organisms of the Salmonella group. Besides
sowing a loopful of the contents directly on MacConkey's agar plate, about half to
one gram of the material was transferred into tetrathionate broth or selenite broth
and sometimes into both when available. After incubating at 37°C for 24 hours
in the case of tetrathionate broth and for 30 hours in the case of selenite broth
[Smith, 1952] the cultures were plated on desoxycholate citrate sucrose-salicin agar
(according to Haines et al. [1947] modification of Leifson's [1935] medium). The
plates were incubated for 48 hours. When non-lactose fermenting colonies appeared,
4 to 6 of them were picked up for testing for urease production in Maslen's [1952]
modification of Chirstensen's [1946] urea medium. The cultures proving negative
for urease production after incubation for 24 hours were collected for study.
Identification of Salmonella cultures
Preliminary differentiation was done on the basis of biochemical reactions accord-
ing to Kauffman [1954]. Cultures showing typical reactions of Salmonella sp.
were confirmed and identified by means of group and factor Salmonella antisera.
Group and factor, somatic (0) and flageller (H), antisera were obtained from Stan-
dards Laboratory, Collindale, London and a few more were received from the Patho-
logy Department, Armed Forces Medical College, Poona (India). Fourteen cultures,
which could not be typed with the help of available antisera were identified by
Salmonella Reference Laboratory, Collindale, London.
RESULTS
Out of a total of 191 cases examined, Salmonella organisms were isolated from
74 cases ; 71 (out of 177) from Government Milk Colony, Aarey, Bombay and
three (out of eight) from Government Dairy Farm, Chakganjaria, Lucknow, Uttar
Pradesh. None of the six cases examined from the Institute Experimental Dairy
Herd at Mukteswar was found positive for Salmonella infection.
Table II shows the types of Salmonella involved in relation to the age at death
Salm. dublin was isolated from 45 cases, Salm. typhimurium from 11 cases and
Salm. enteritidis from four cases. Other species isolated from the remaining 14 cases
have been recorded, apparently, for the first time in this country. Some species
such as Salm. weltevreden, Salm. richmond and Salm. nchanga have been occasionally
reported from cases of gastroenteritis in man. There appears to be no record of
their isolation from animals. Salm. newport, which was isolated from two cases in
this series and Salm. butantan and Salm. chester, which accounted for one case each
have often been isolated from cases of infantile diarrhoea and gastroenteritis in man.
Salm. newport is one of the most common types met with in outbreaks of food poison-
ing in mam in Great Britain and the U.S.A. Birds, particularly chickens, turkeys
and ducks and pigs appear to be the chief animal reservoirs of this Salmonella species