Hemolytic Streptococci from Tonsils of Cow,Hog,and Sheep

Abstract

Investigations in our laboratories have demonstrated the constant occurrence of hemolytic streptococci of the beta type in the human throat and tonsillar crypts. In excised tonsils of children and adults these streptococci can be isolated from the depths of the crypts in 97%, 1 often in predominant numbers and occasionally in pure culture. These organisms conform to the virulent human type in their cultural and biological reactions. In 13.8% the streptococci from these tonsils resemble the Streptococci epidemicus, the mucoid encapsulated streptococcus identified with the bovine mastitis responsible for epidemic septic sore throat. 2 The Streptococcus epidemicus recovered from milk and throat alike correspond to the human type of streptococci. Other streptococci responsible for bovine mastitis appear to be of the bovine type and apparently are harmless to human beings.

The present investigation was to determine the presence of hemolytic streptococci in the tonsils of cattle and to study their biologic properties. The tonsils were obtained from the Chicago stockyards, during the months of October, November, and December, 1935. The pharyngeal structures containing both tonsils were brought to the laboratory and cultures were made within 2 to 3 hours after slaughter.

A transverse section through the substance of the tonsil beneath the mucous membrane was made with a sterile knife and the cultures made from the depths of the exposed crypts. Usually a small amount of debris or secretion was obtained with a loop and a dilution made in sterile salt-solution. Dilution-pour-plates were examined after 24 and 48 hours at 37.5°C. The medium was infusionagar and 5% defibrinated human blood, with ascitic fluid (20%) to render mucoid organisms prominent. 3