The Enterococci: With Special Reference to Their Association with Human Disease

Abstract

The literature on human infections with enterococci is reviewed, and the results of a study of 34 strains, 23 from human pathologic sources, and 11 from other sources, are reported. Enterococci have been found in a great variety of human ailments. They appear to be important causal agents in some cases of endocarditis, intestinal disorders, abdominal infections due to injury of the intestinal tract, infections of wounds inflicted during war, and infections of the urinary tract. The following characteristics distinguished the enterococci from other streptococci : Reaction in serum of group D according to Lance-field''s precipitin test; growth at 10[degree] and 45[degree]C; growth in media containing 6.5% NaCl; growth in media having an initial pH value of 9.6; growth in media containing 40% bile. The hardiness of the enterococci is of practical significance in that they are resistant to the sulfonamides and penicillin. The following characteristics are useful in distinguishing subgroups or species of enterococci: Agglutinative reaction; sensitivity to bacteriophage D-693; growth in milk containing 0.1% methylene blue; survival at 60[degree]C for 30 mm.; production of acid from sucrose, mannitol and sorbitol. The type of hemolysis and liquefaction of gelatin, characteristics on which differentiation of species hitherto have been based, were found to be uncorrelated with other significant characteristics. The data indicate that enterococci pathogenic for man may be derived from the flora of normal human intestines, or from the tissues or intestines of various spp. of animals.