Acid from glucose, lactose, trehalose and sorbitol. May or may not ferment sucrose, glycerol, mannitol and salicin. No acid from arabinose, raffinose or inulin. Gelatin not liquefied. Sodium hippurate not hydrolyzed. Some strains may hydrolyze starch or split esculin. Ammonia produced from arginine. Not pathogenic. Source: Isolated from raw milk and the bovine udder. Habitat: Unknown. 2. Streptococcus sp. Lancefield and Hare. (Large colony group G, Lancefield and Hare, Jour. Exp. Med., 60, 1934, 633; Lance- field, The Harvey Lectures, Series XXXVI, 1940-1941, 251.) Spherical or ovoid cells 0.6 to 1.0 micron in diameter; occur in medium-sized or long chains. Serologj^: Belongs to Lancefield's group G. At least three serological tj'pes of the large-colony group G streptococci have been established (Simmons and Koegh, Austral. Jour. Exp. Biol. Med. Sci., 18, 1940, 151). May contain a common protein antigen with Streptococcus equisimilis which sometimes gives rise to confusing cross-reactions. Griffith's type 16 belongs to this species. Action on blood: Broad-zone beta hemol- j'sis on blood agar. Area of hemolysis may be much larger than that produced by Streptococcus pyogenes. Soluble hemolysin produced that is identical to streptolysin O. Colony form: Matt colonies similar to those of Streptococcus pyogenes and Strepto- coccus equisimilis are produced characteris- tically. May or may not be fibrinolytic (Sher- man, Bact. Rev., 7, 1937, 1). Temperature relations: No growth at 10° and, with few exceptions, no growth at 45° C. Does not survive 60° C for 30 min- utes. Tolerance tests : Fails to grow in presence of 6.5 per cent NaCl or in skim milk con- taining 0.1 per cent methylene blue. Gen- erally more tolerant to methylene blue than Streptococcus pyogenes. No growth in broth adjusted to pH 9.6 or on blood agar con- taining 40 per cent bile. Litmus milk: Acid, some strains curdle; litmus not reduced before curdling. Final pH in glucose broth, l)etween 4.8 and 5.2. Acid produced from glucose, lactose, sucrose and trehalose. Glycerol is fer- mented when incubated aerobically. Salicin may or may not be fermented. Inulin fer- mented by a few strains. No acid from raf- finose, mannitol or sorbitol. Starch may be hydrolyzed by some strains. Gelatin not liquefied. Sodium hippurate not hydrolyzed. Es- culin usually split. Ammonia produced from arginine. Source: Obtained from the human throat, nose, skin, vagina and feces. Also found in the throat of a number of domestic ani- mals, especially the dog. May be associated with a variety of animal diseases. Habitat: Human respiratory tract and vagina; throats of domestic animals. This group of streptococci deserves spe- cies recognition, but no suitable name has been proposed. More than one variety or species may be included among these large- colony group G streptococci (Sherman, Bact. Rev., 1, 1937, 1). Some strains, es- pecially those that are fibrinolytic, are very difiicult to differentiate from Streptococcus pyogenes by means other than serological methods. 3. Streptococcus sp. Hare. (Group K, Hare, Jour. Path. Bact., 41, 1935, 499.) Spherical cells in medium-sized to long chains. Gram-positive. Serology: Established as group K. Action on blood: Small, incomplete zones of hemolysis on 8 per cent blood agar. No soluble hemolysin produced. Colony forms: Moist and transparent with crenated edges; 0.8 to 1.3 mm in di- ameter after 48 hours. Not fibrinolytic. Tolerance test: Does not grow on 10 per cent bile blood agar. Final pH in glucose broth, between 5.1 and 5.4. Acid from glucose and generally from lac- tose. May or may not ferment salicin. Acid generally not produced from trehalose, mannitol or sorbitol.
