320 



MANUAL OF DKTi.EMINATIVt BACTERIOLOGY 



Toxin : No evidence of an erythrogenic 

 toxin. 



Fibrinolysin : Does not dissolve human 

 fibrin. 



Serology: Group B of Lancefield (Jour. 

 Exp. Med., Ifl, 1933, 571). Three anti- 

 genic types have been separated which 

 appear to be associated with the carbo- 

 hydrate and not the protein fraction. 



Facultative anaerobe. 



Source : Isolated from milk and tissues 

 from udders infected with mastitis. Oc- 

 casionally reported from human sources 

 (Lancefield, Jour. Exp. Med., 57, 1933, 

 571 ;Hare,Jour. Path. Bact., 4^, 1935,499). 



Habitat : Udder of cattle with mastitis. 



6. Streptococcus salivarius Andrewes 

 and Horder. (Lancet, 2, 1906, 712 ; Slrej)- 

 tococcus cardio-arthritidis Small, Amer. 

 Jour. Med. Sci., 173, 1927, 103.) From 

 Latin salivarius, slimy, clammy; M. L., 

 related to saliva. 



Description based on studies by Saf- 

 ford, Sherman and Hodge, Jour. Bact., 33, 

 1937, 263 and Sherman, Niven and Smiley, 

 Jour. Bact., 45, 1943, 249. 



Spherical or ellipsoidal cells, 0.6 to 0.8 

 micron in diameter, usually in short 

 chains. Long axis of cell lies in axis of 

 chain. Cells are relatively large in liquid 

 media, especially milk. Gram-positive. 



Gelatin stab: Filiform growth. No 

 liquefaction. 



Plain nutrient agar: Colonies white, 

 small, not more than 0.5 mm in diameter. 

 Notwithstanding rather vigorous growth 

 on artificial culture media, cultures die 

 out readily. 



Nutrient agar containing 5 per cent 

 sucrose or raffinose produces a large, clear, 

 soft, mucoid colony about the diameter of 

 those produced by coliform bacteria and 

 yeasts. This is quite distinctive as no 

 other known species of streptococcus 

 (except occasional strains of Streptococcus 

 bovis) produce colonies of this type on 

 sucrose or raffinose agar. The polysac- 

 charide produced is a soluble levan, some 

 strains producing in addition a smaller 



amount of insoluble dextran (the poly- 

 saccharide in the Streptococcus bovis colo- 

 nies is a dextran) . 



Action on blood agar : Indifferent 

 (gamma hemolysis of Brown, Rockefeller 

 Inst. Med. Res., Monograph 9, 1919, 8). 

 No soluble toxin and no hemolysin has 

 been demonstrated 



Broth: Variable. Loose, fiocculent de- 

 posit with clear supernatant fluid and 

 long chains, or uniform or granular tur- 

 bidity with small deposit and short 

 chains. No pellicle. 



Litmus milk: Acidified and curdled 

 promptly by all lactose -fermenting 

 strains. Completely reduced but only 

 after curdling. No digestion. 



Potato: Slight growth. Difficult to 

 detect. 



Acid from glucose, maltose, sucrose, 

 raffinose, inulin and salicin. No acid 

 from glycerol, mannitol, sorbitol, arabi- 

 nose or xylose. Trehalose and lactose 

 usually fermented. 



No hydrolysis of sodium hippurate and 

 arginine. Splits esculin. Starch is not 

 liydrolyzed. 



Ammonia is not produced from peptone. 



Chemical tolerance : Tolerates 2 per 

 cent but not 4 per cent NaCl. Final pH 

 in glucose broth between 4.4 and 4.0. 

 No growth at pH 9.6. Methylene blue 

 0.01 per cent and 0.1 per cent not tol- 

 erated. Not soluble in bile but inhibited 

 by 30 per cent bile in blood agar. 



Catalase not produced. 



Temperature relations : Optimum 

 growth 37° to 43°C. Growth at 45°C. 

 No growth at 47°C. No growth at 10°C. 

 Does not survive 60°C for 30 minutes. 



Facultative anaerobe. 



Serology : No group antigen has been 

 demonstrated. Contains several sero- 

 logical types. 



Source : Saliva and sputum in various 

 pulmonary infections, apical abscesses of 

 teeth, carious lesions of teeth, intestinal 

 tract. 



Habitat: Human mouth, throat and 

 nasopharynx. 



