SELECTED ARTICLE
EFFECT OF LOCAL INJECTIONS OF PENICILLIN ON STAPHYLOCOCCI
IN THE COW'S UDDER*
By LOUIS A. KLEIN, V.M.D., DAVID W. CRISMAN, B.S., D.V.M., and JOHN W. MOOR, V.M.D.,
Philadelphia, Pennsylvania
T HE results obtained with local injections of penicillin in the treatment of empyema, mastoiditis
and chronic wound sinuses in man due to staphylococcus or streptococcus infection, as reported
by the Floreys, 1 the National Research Council's Committee on Chemotherapeutic and Other Agents, 2
and by Lyons, 3 suggest that intramammary injections via the teat canal might be effective in
catarrhal mastitis, also called chronic mastitis.
In this form of mastitis, conditions exist that have been found favourable to the action of local
injections in treating human patients, viz., the infection is situated in a closed cavity or space from
which the contents can be readily withdrawn, and the infection is localized and accessible. Frei 4
and other investigators have found that in catarrhal mastitis due to streptococci, it is the excretory
channels that are involved, usually the milk cistern and the larger ducts primarily, while clinical
symptoms indicate that the disease is similarly situated when it is caused by staphylococci. In this
location the causative organisms are readily accessible to solutions introduced through the teat
canal while any exudate present can be readily milked out before making an injection. Most clini-
cians with experience in treating human patients with the drug are of the opinion that local injections
should be supplemented by intravenous or intramuscular injections but recovery or improvement
has been obtained in the conditions mentioned above with local injections alone.
It was decided to test the action of intramammary injections of penicillin on the staphylococci
which cause mastitis and also to determine the effect on the cow, especially on the under tissue. The
penicillin used was prepared specifically for this study by Dr Waltee Kocholaty, Thos. H. Dougherty,
Jr. Fellow in Research in Brucellosis, University of Pennsylvania School of Medicine, in July, 1943.
Staphylococci are one of the causes of catarrhal mastitis and the symptoms they produce are
similar to those caused by streptococci. They also cause a severe type of acute perenchymatous
mastitis which is often complicated by sepsis, and gangrene of the udder is frequently associated
with it. This type of udder infection was selected because clinical results show that it is more re-
sistant to the agents now used in intramammary injections than the mastitis streptococci, and
also because in in vitro tests penicillin was found to be more effective than some of these agents
against Staphylococcus aureus. Fleming 5 found it four times as potent as sulfathiazole and twenty
times as potent as sulfapyridine against this organism, and Heilman and Herrell 6 found it more
effective than gramicidin.
Identification of mastitis staphylococci
In examining samples of milk or other udder secretions for the staphylococci which cause mastitis,
it is necessary to differentiate them from the nonpathogenic cocci, usually called micrococci, which
are normally present in the udder and the milk.
* From the School of Veterinary Medicine, University of Pennsylvania, Philadelphia.
In accordance with regulations formulated by the War Production Board, concerning the production and use of peni-
cillin, permission was requested and received by Dr G. A. Dick, Dean of the School of Veterinary Medicine, to produce
and use a limited amount of penicillin for the purpose of this study. At the request of Dr A. N. Richards, Vice President
of the University of Pennsylvania and Chairman of the Committee on Medical Research of the Office of Scientific Research
and Development, publication of the findings of this study has been withheld until the present. The contents of this paper
were, however, submitted in confidence on April, 29, 1944, to the Bureau of Animal Industry, U. S. Department of Agricul-
ture, and to the Pennsylvania Department of Agriculture.
Publication of this article has been cleared through the Committee on Medical Research, National Research Council.
This study was facilitated by laboratories of the University of Pennsylvania, which receive financial support from the
U. S. Department of Agriculture, the Department of Agriculture of the Commonwealth of Pennsylvania, the Smith Kline
and Fresh Laboratories Inc., and the Thos. H. Dougherty Jr. Fund.
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