Abstract
Sherman 1 recently offered a method of classifying the streptococci based mainly on physiological∗ tests which include growth at 10°C and at 45°C, growth in the presence of 6.5,% NaCl or in the presence of 0.1% methylene blue, liquefaction of gelatin, and reaction in litmus milk.
It was the purpose of the study here reported to investigate the biochemical behavior of streptococci isolated from cases of endocarditis and to attempt to correlate their reactions in Sherman's tests with the reactions of the salivary streptococci or of the enterococci. The organisms investigated consisted of 20 strains isolated from the blood of cases which were clinically diagnosed as cases of endocarditis. These strains were submitted to us through the kindness of various hospitals throughout St. Louis and other cities of the United States. All organisms were found to be bile-insoluble.
Table I shows the reactions of the endocarditis-organisms in the physiological tests which Sherman considers to be of primary differential value. Twelve of the organisms tested are similar to Streptococcus salivarius according to Sherman's tests, 3 correspond to Streptococcus fecalis and 2 to Streptococcus zymogenes. Only in the case of the strain labeled Coffman is there any variation from the rule. This strain resembled Streptococcus fecalis in other ways but did not reduce the litmus of litmus milk until after the milk had been clotted. However, the other strains which resembled Streptococcus fecalis gave the typical reaction in milk, i. e., reduction of the litmus before coagulation. The strains which resembled Streptococcus zymogenes showed the strong reduction which is typical for these organisms. Peptonization also occurred, additional evidence of their property of proteolysis.
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