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13
September, 1909. " Pathological Department,
St. Bartholomew's Hospital, E.C.
BACTERIOLOGICAL REPORT
By Dr. M. H. Gordon.
Sir,—During the month of June, 1909, an extensive outbreak of scarlet fever in the metropoltian
district having followed the consumption of certain milk derived from two farms, and the circumstances
of the outbreak having been found on investigation to point to the cows at these farms as a
likely source of the infection, I was invited to investigate the matter from the bacteriological standpoint.
Accordingly, on June 23rd, I proceeded, in the company of Dr. Hamer and Mr. Dunbar, to the
two farms in question, X1 and X2. On arrival at these farms Mr. Dunbar examined each cow in turn
and drew my attention to such abnormalities as were present.
At both farms, a proportion of the cows showed on their teats, and occasionally on their udder,
a discrete papular eruption which in some cases had passed to a pustular stage. At the date of my
visit this eruption was on the wane, but I was able to collect material from the eruption on two cows
at each of the two farms.
I have made a bacteriological examination of the material thus obtained, and also of material
removed by Dr. Hamer from cows at farm Xa on a visit a few days previously, with the following
results :—
1. Microscopical examination.
Coverglass preparations of the material showed the presence of one kind of micro-organism only,
namely, Gram positive diplococci.
2. Cultures.
Cultures were made of the material on agar and serum, incubated at 37° C.
In all cases these cultures yielded a mixture of staphylococci and streptococci. The latter were
in the majority. The staphylococci were all found to be examples of staphylococcus aureus and were
not tested further.
The streptococci were isolated in pure culture and their character investigated in detail, with
the results seen in the accompanying table.
It will be observed that six of the seven streptococci tested had identical reactions.
The single streptococcus (2a) that differed from the rest is seen upon its reactions to be an
example of streptococcus faecalis, and was probably a contamination.
The type of streptococcus to which the rest of the streptococci conform is closely allied to two
types of streptococci that have been described.
The first of these was obtained by Drs. Andrewes and Horder from the fauces of persons suffering
from scarlatina, and it was termed by them streptococcus anginosus. The streptococcus from the
cows at farms X1 and X2 was like this streptococcus in general features, except that its chains were
somewhat shorter, and neutral red was not reduced. Furthermore, the streptococcus from cows at
farms X1 and X2 failed to exhibit pathogenicity for the mouse.
The second type of streptococcus which the streptococcus from cows at farms X1 and X2 also
closely approaches is a type found by Dr. W. G. Savage to be the most frequently found in mastitis
in cows. Dr. Savage's streptococcus mastitidis is chiefly differentiated by him from streptococcus
anginosus by the fact that it is less virulent for mice than streptococcus anginosus, but chiefly because
streptococcus mastitidis produces mastitis in goats, whereas streptococcus anginosus does not.
I have been unable to inject this streptococcus from the cows on farms X1 and X2 into goats
so that I am unable to state which of these two streptococci that micro-organism most closely
resembles.
Before concluding this report, I venture to draw attention to a recent observation that may
have valuable application in future outbreaks of scarlatina in which infection of the milk by human
agency is apparently excluded, and the cow itself is under suspicion as the source of the infection.
The discovery of Bordet and Gengou, of the Pasteur Institute, of the " Fixation of Complement "
method has provided us with a specific test whereby we can recognise the presence of specific antibodies
in the blood of an animal affected by a given infection.
Schleissner, of Prague, in a recent paper entitled " Bacteriological and Serological Studies in
Scarlet Fever" (Wien. Klin. Woch., xxii., 16, 1909. p. 553), has applied this test of fixation of complement
to the serum of persons suffering from scarlet fever, with the result that he finds that by this,
test the serum of scarlatina patients can be shown to contain a specific antibody for the scarlatinal
streptococcus, from the second up to the sixth week of this disease. Control experiments made in
the same way with serum from normal persons, and from persons suffering from diseases other than
scarlet fever, were negative in this sense.
In future outbreaks of milk scarlatina, therefore, by applying this test to the serum of cows
under suspicion of having originated the outbreak, it should be possible to decide whether their blood
contains the same specific antibody than is found present in the blood of persons suffering from scarlet
fever between the second and sixth week of the attack. The information thus obtained may be found
to furnish a valuable piece of evidence in elucidating the causation of such outbreaks.
I have the honour to remain, Sir,
Yours faithfully,
M. H. Gordon.
Sir Shirley Murphy.