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characteristic of α-toxin; and (iii) in most cases,
immediately by comparatively narrow zones of
ear haemolysis and peripherally by wider zones
darkening, indicative of both α-and ß-toxin.
storage in the cold brought about progressive changes
in these different types of haemolysis characteristic
of pathogenic staphylococci of bovine origin. Super-
social colonies were generally haemolytic. A few
rains studied were found to produce soluble hae-
olysin ; they were actively proteolytic (gelatine),
generally fermented mannitol and invariably formed
coagulase for rabbit plasma.
Staph. pyogenes was encountered in 204 quarters
of 126 cows and two buffaloes, i.e. in nearly 24
per cent of all animals examined. No herd was
found completely free from infection with this
organism and in some the incidence was nearly 60
per cent. In many cases the colonies obtained were
very numerous, and it seems that Staph. pyogenes
may be regarded as the commonest cause of udder
infections in this country. It was, at any rate,
found to be common in milk from cows which had
developed acute inflammation of the udder, generally
post-partum. With suitable treatment and care,
such udders tended to return to normal, but the
worst-affected quarters continued to excrete the
organism in gradually decreasing numbers for
some time. Similar affections also seem to be
associated with other bacteria and occasionally,
especially when examined quite early in the onset,
it may not be possible to recover any organism of
pathogenic significance.
DISCUSSION
It is hoped that this work may provide preliminary
information on the general bacteriology of the
diseased bovine udder in India and may furnish some
information on the incidence of different types of
streptococci, staphylococci, and other organisms
recoginzed to be commonly associated with the
disease in other countries.
The methods used for streptococci were restricted
to their cultural and biochemical characters. Sero-
logical typing was not undertaken, partly because
objects of the work did not demand it, partly because
the typical strains of Str. agalactiae can be recognized
without much difficulty by the methods used and
partly because facilities for serological work were
not available.
Since systematic examination for udder induration,
etc. was not done, it is not possible to give accurate
information about the correlation between the
different bacteria and the various kinds of udder
affections. However, some information of a
general character, based partly on the clinical history
supplied and partly on a few clinical examinations
has been incorporated.
SUMMARY
This paper gives an account of preliminary in-
vestigations, carried out from 1935 to 1942, on the
general bacteriology of mastitis in cows and buffaloes
in India. Systematic examination of the udder
for indurations, etc. was not taken up.
The first section deals with the examination of
over 100 specimens of udder secretion from 85 cows,
including a few buffaloes, affected with clinical
mastitis in different parts of the country. The
second section is concerned with a systematic exa-
mination of 541 cows from about 15 different dairy
herds in the northern India.
3. Bacterial infections of the bovine udder in
India correspond fairly, in type and cause, to similar
infections in other countries.
The existence of Str. agalactiae has been establish-
ed in both cows and buffaloes at a number of places,
but the incidence is low. In the preliminary work,
several strains of Str. agalactiae were recovered
from cows and buffaloes affected with clinical mastitis.
In the systematic survey, ten authentic strains
and ten suspicious strains of Str. agalactiae were
isolated from cows and buffaloes belonging to
five herds.
Other streptococcus groups occasionally found
were Str. dysgalactiae in one cow with subacute
mastitis, Str. uberis in two cows with a history of
mastitis, and Str. subacidus from a few cows mostly
with a more or less acute mastitis. There were
also several strains of streptococci, mainly from
apparently healthy quarters, which were not properly
classified. There was no authentic case of Str.
pyogenes (Lancefield group A) infection.
Among other well-recognized pathogens of the
bovine udder were :
(a) Staph. pyogenes, of which some 250 strains
were isolated from nearly 140 cows; this organism
was held responsible, alone or in conjunction with
others, for some acute post-partum mastitis and for
much chronic low grade mastitis.
(b) Corynebact. pyogenes, was isolated, often in
pure culture, from about five cows and one buffalo
with suppurative mastitis.
(c) Bact. coli, and other coliforms, were isolated
from several animals and seemed to be definitely
pathogenic in at least one cow and one buffalo.
(d) Other organisms of possible importance were
three strains of Proteus and one strain of Pseudo-
monas.
ACKNOWLEDGEMENTS
Space does not permit individual acknowledge-
ment to all officers who were on different occasions
connected with this work. The two outstanding
contributions have been from Messrs P.R.K. Iyer and
B. N. S. Chowdhury. The former was responsible