FAMILY X. LACTOBACILLACEAE 



527 



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. 



