Page:Bergey's manual of determinative bacteriology.djvu/539

 merited. Raffinose fermented bj' the group G strains. Inulin, glycerol, mannitol and sorbitol not fermented. Starch not hydrolyzed. Gelatin not lique- fied. Sodium hippurate not hydrolyzed. Escu- lin split. Ammonia produced from arginine. Oxidizes butja-ic acid with the production of hydrogen peroxide (Niven, Evans and White, Jour. Bact., J^9, 1945, 105). Requires folic acid for growth in simplified media (Niven, Washburn and Sherman, Jour. Bact., 51, 1946, 128). Reciuires high carbon dioxide tension or an unsaturated fatty acid for growth in simplified media (Deibel, Thesis, Univ. of Chicago, 1952). Comments: All of the minute streptococci do not adhere to the original description of Streptococcus anginosus as given by An- drewes and Border. The minute streptococci comprise a homogeneous group based upon physiological characteristics other than those originally employed by these investi- gators ; also it will be noted that this species, as herein described, contains representa- tives that belong to two different serological groups. Further study of these microor- ganisms is needed to establish definitely the validity of this precedent. Minor differences between the group F and the minute group G streptococci may warrant the establish- ment of two separate varieties within this species or an ultimate separation into two separate species (Sherman, Bact. Rev., /, 1937,3). Source: Human throat, sinuses, abscesses, vagina, skin, feces. Has been associated with glomerular nephritis and various types of mild respiratory diseases. Habitat: Human respiratory tract. 8. Streptococcus agalactiae Lehmann and Neumann, 1896. (Streptococcus de la mammite, Nocard and MoUereau, Ann. Inst. Past., 1, 1887, 109; Streptococcus nocardi Trevisan, I generi e le specie delle Batteriacee, 1889, 30; Streptococcus agalac- tiae contagiosae Kitt, Bakterienkunde, Wien, 1893, 322; Lehmann and Neumann, Bakt. Diag., 1 Aufl., 2, 1896, 126; Strepto- coccus ttiastitidis Migula, Syst. d. Bakt., 2, 1900, 19.) a.ga.lac'ti.ae. Gr. noun agalactia want of milk, agalactia; M.L. gen. noun agalactiae of agalactia. Spherical or ovoid cells 0.6 to 1.2 microns in diameter, occurring in chains of seldom less than four cells and frequently very long. Chains may appear to be composed of paired cocci. Serology: Constitutes Lancefield's group B. May be subdivided into a number of serological types by the precipitin tech- nique on the basis of the capsular carbohy- drate "S" substance. The type-specific polysaccharides appear to have a direct relationship to virulence, and the antibodies to which they give rise are concerned with the specific protective action of immune sera. Some strains may lack the "S" sub- stance. There is a difference of opinion as to whether the serological types indigenous to man and cattle are distinct (Lancefield, Harvey Lectures, Ser. XXXVI, 1940, 251; Simmons and Keogh, Austral. Jour. Exp. Biol. Med. Sci., 18, 1940, 151; Brown, Proc. Fifth Internat. Congress Microbiol., Rio de Janeiro, 1950, in press). Action on blood: About half the strains produce narrow but clear zones of hemoly- sis on blood agar. A few may produce broad zones of hemolysis. The other strains pro- duce greening (alpha hemolytic) reaction. The hemolytic strains produce a soluble hemolysin that is moderately sensitive to heat and acid and that is distinct from streptolysins O and S. Some strains produce a yellow, orange or brick-red pigment in stab cultures. May also be noted as an orange sediment in broth cultures, especially when starch is added. Not fibrinolytic. Temperature relations: Optimum tem- perature, 37° C. No growth at 10° or 45° C. Does not survive 60° C. for 30 minutes. Tolerance tests : Usually grows in presence of 4 per cent NaCl but not in 6.5 per cent NaCl. Does not grow in milk containing 0.1 per cent methylene blue or in broth ad- justed to pH 9.6. Usually grows on blood agar containing 40 per cent bile.