Page:Bergey's manual of determinative bacteriology.djvu/542

 strains produce colonies on sucrose agar resembling small bits of broken glass. Acid from glucose, maltose, sucrose and usually from lactose and salicin. A minority of the strains ferment raffinose and treha- lose. No acid from inulin, mannitol, sor- bitol, glycerol, arabinose or xylose. Sodium hippurate and gelatin not hy- drolyzed. Esculin is split by a minority of the strains. Starch may be hydrolyzed feebly by some strains. Ammonia may or may not be produced from arginine. Some strains oxidize butyric acid with the production of hydrogen peroxide and acetic acid (Wolin, Evans and Niven, Jour. Bact., 6J^, 1952, 531). Comments: This species comprises the heterogeneous group of greening strepto- cocci associated with the human respiratory tract. It has no unique identifiable charac- teristic, and some non-hemolytic varieties of the pyogenic group may be confused with it. The species may yield to more incisive methods of segregation and more accurate characterization of its constituent units. Source: Saliva, sputum and intestinal tract of the human. Ordinarily not consid- ered pathogenic but may be recovered from ulcerated teeth and sinuses and from the blood and heart lesions in subacute endocar- ditis cases. Habitat: Human mouth, throat and naso- pharynx. 12. Streptococcus bovis Orla-Jensen, 1919, emend. Sherman, 1937. (Orla-Jensen. The Lactic Acid Bacteria, 1919, 137; Sher- man, Bacteriological Reviews, 1, 1937, 57.) bo'vis. L. noun hos a cow; L. gen. noun hovis of a cow. Spherical or ovoid cells, 0.8 to 1.0 micron in diameter, occurring in pairs and chains. Some occur in long chains. Gram-positive. Serology: This species is serologically heterogeneous. Many serological types are known to occur. Some strains cross-react with group D sera (Sherman, Jour. Bact., 35, 1938, 81). Shattock (Jour. Gen. Micro- biol., S, 1949, 80) claims that by special methods of preparing the cellular extracts, the group D antigen can be demonstrated. Action on blood: The changes exhibited vary from strong greening (alpha hemolytic) to no observable change (gamma hemoly- tic). No soluble hemolysin produced. Generally uniform turbidity with some sediment produced in broth cultures. Some strains tend to die out rapidly in artificial media. Temperature relations : Growth at 45° but not at 10° C. Survives 60° C. for 30 minutes. Tolerance tests: No growth in broth con- taining 6.5 per cent NaCl. No growth at pH 9.6. May tolerate 0.01 per cent, but not 0.1 per cent, methylene blue in milk. Growth occurs on blood agar containing 40 per cent bile. Litmus milk: Acid; usually curdles with litmus reduction after curdling. No diges- tion. Final pH in glucose broth, between 4.0 and 4.5. Some strains synthesize a dextran from sucrose resulting in the production of large, mucoid colonies on agar media containing 5 per cent sucrose. Acid from glucose, fructose, mannose, galactose, maltose, lactose, sucrose, raf- finose and salicin; sometimes from xylose, arabinose, trehalose, inulin, mannitol and sorbitol. No acid from glycerol. Starch is hydrolyzed. Occasional strains hydrolyze sodium hippurate. Gelatin not hydrolyzed. Esculin split. Ammonia is not produced from arginine. Distinctive characters: This species is characterized by its temperature limits of growth, its bile tolerance and its ability to hydrolyze starch. A significant proportion of the strains from bovine sources do not, however, fit the above description. Further study of the streptococci from bovine sources is indicated. Source: Alimentary tract of the cow. Sometimes found in large numbers in hu- man feces. May be encountered in blood and heart lesions of certain cases of subacute endocarditis (Niven, Washburn and White, Jour. Bact., 55, 1948, 601). Habitat: Bovine alimentary tract. 13. Streptococcus equinus Andrewes and Border, 1906. (Lancet, 2, 1906, 712.) e.qui'nus. L. adj. equinus pertaining to a horse.