318 



MANUAL OF DETERMINATIVE BACTERIOLOGY 



No hydrolysis of sodium hippurate. 



Temperature relations : Optimum tem- 

 perature 37 °C. Growth slow at 20°C. 

 No growth at 10°C or 45°C. Does not 

 survive 60°C for 30 minutes. 



Chemical tolerance : Does not tolerate 

 6.5 per cent NaCl ; final pH in glucose 

 broth 4.8 to 5.5. Methylene blue is not 

 tolerated 0.01 per cent to 0.1 per cent. 

 Inhibited by bile but not soluble. 



Action on blood : On blood-agar, colo- 

 nies are small and watery, dry out rapidly 

 leaving flat glistening colony. Well-de- 

 fined wide clear zone of hemolysis (beta 

 hemolysis). Growth in serum broth 

 gives a hemolysin active on horse cor- 

 puscles, less so on those of sheep and 

 guinea pig. 



Toxin: Subcutaneous injection causes 

 necrosis, other evidence of toxin produc- 

 tion is defective. 



Fibrinolysin : Usually does not lyse hu- 

 man fibrin ; some strains reported to do so. 



Serology: A member of Lancefield's 

 Group C (Jour. Exp. Med., 57, 1933, 571) ; 

 cross precipitation with Species No. 2 

 (animal pyogenes) of Edwards (Jour. 

 Bad., 27, 1934, 527). Cultures have been 

 poor antigens for production of aggluti- 

 nating serum and results have been un- 

 satisfactory. Immunized rabbit serum 

 may protect mice from infection, to which 

 mice are very susceptible. 



Pathogenicity high for white mice, low 

 or no virulence for rabbits and guinea 

 pigs. 



Facultative anaerobe; growth in pri- 

 mary culture often better in depth of 

 medium. 



Source : Pus from lesions and mucous 

 membrane of upper respiratory tract of 

 horses. Evidence of occurrence in man is 

 unconvincing. 



Habitat: Found only in strangles in 

 horses. 



4. Streptococcus equisimilis Frost and 

 Engelbrecht. (Human C, Ogura, Jour. 

 Jap. Soc. Vet. Sci., 8, 1929, 174; Edwards, 

 Jour. Bact., S3, 1932, 259; ibid., 25, 1933, 

 527; Sherman, Bact. Reviews, 1, 1937, 35; 



Frost and Engelbrecht, A Revision of 

 the Genus Streptococcus, privately pub- 

 lished, 1936, 3 pp. and The Streptococci, 

 1940, 45.) From M. L., derived tp mean 

 similar to equi. 



This species is apt to be confused with 

 Streptococcus equi Sand and Jensen, but 

 it is not as fastidious in its growth re- 

 quirements and shows greater tolerance of 

 methylene blue, lyses human fibrin and 

 ferments glycerol and trehalose. It may 

 or may not ferment lactose. 



It is also apt to be confused with Strep- 

 tococcus pyogenes Rosenbach except for 

 its greater tolerance of methylene blue, 

 glycerol fermentation and especially 

 Lancefield's serological grouping (Jour. 

 Exp. Med., 57, 1933,371). 



Spheres: Gram-positive. 



Gelatin : Not liquefied. 



Litmus milk: Acid, may be curdled; 

 litmus not reduced before curdling. 



Acid from glucose, maltose, sucrose, 

 trehalose and glycerol; may or may not 

 form acid from lactose and salicin. No 

 acid from arabinose, raffinose, inulin, 

 mannitol or sorbitol. 



No hydrolysis of sodium hippurate but 

 may hydrolyze starch and esculin. 



Ammonia is produced from peptone. 



Temperature relations : No growth at 

 10°C and 45°C. Does not survive 60°C 

 for 30 minutes. 



Chemical tolerance : Does not tolerate 

 6.5 per cent NaCl. Final pH in glucose 

 broth 5.4 to 4.6; no growth at pH 9.6. 

 Methylene blue 0.1 per cent not tolerated, 

 but Edwards (Kentucky Agr. Exp. Sta- 

 tion Bull. 356, 1935; confirmed by Davis 

 and Guzdar, Jour. Path, and Bact., 43, 

 1936, 197) finds resistance to 0.000025 mo- 

 lar methylene blue in infusion-casein 

 digest broth. Rarely grows on 40 per 

 cent bile-blood agar. 



Action on blood: Beta hemolysis. 



Fibrinolysin: Dissolves human fibrin. 



Serology : Lancefield (loc. cit) Group C. 



Facultative anaerobe. 



Source : Human nose and throat, vagina 

 and skin ; erysipelas and puerperal fever. 

 Uncommon in domestic animals and usu- 



