Page:Bergey's manual of determinative bacteriology.djvu/561

 No toxin and no hemolysin. Distinctive characters: Strongly acidifies media; coagulates milk. Source: Isolated from lochia and uterus in puerperal sepsis; also from cases of gan- grene of the lung, pleurisy, bronchiectasis and appendicitis. Habitat : Found in the human respiratory and digestive tracts and in the vagina. 9. Peptostreptococcus evolutus (Pre- vot, 1924) Smith, comb. nov. (Streptococcus Sch. (Schwarzenbek), Graf and Wittneben, Cent. f. Bakt., I Abt., Orig., U, 1907, 97; Streptococcus evolutus Pr6vot, Thes. M6d., Paris, 1924; Streptococcus Schwarzenbeck (sic) Ford, Textb. of Bact., 1927, 455: also see Weiss and Mercado, Jour. Inf. Dis., 62, 1938, 181.) e.vo.lu'tus. L. part. adj. evolutus unrolled. Description taken in part from Prevot (Ann. Sci. Nat., Ser. Bot., 15, 1933, 199). Spheres, 0.7 to 1.0 micron in diameter, averaging 0.7 micron, occurring in pairs or in short and long chains. Pleomorphic. Often appear as short, ovoid rods with rounded ends. Gram-positive. Gelatin: Liquefaction. Deep agar colonies : Lenticular or rosettes. Growth occurs about one cm beneath the surface; after a transfer the second gen- eration may show a ring of growth in the middle of this sterile zone. This is the charac- teristic alternate zones appearance. Suc- cessive generations may grow fully when exposed to the air. Colonies usually become brownish with age. Glucose broth: Abundant growth resem- bling bread crumbs. Medium strongly acidified (pH 5). A small quantity of lactic acid is produced. Peptone broth: Rapid growth; no general turbidity; precipitating, flocculent growth on the wall of the tube; indole not pro- duced. Blood agar: No change, sometimes green- ing. Litmus milk: Acid; curdled in 24 hours; clot retracts and fragments; slight peptoni- zation with some strains. Coagulated protein not attacked. Acid from glucose, fructose, galactose. sucrose, lactose and maltose. Arabinose sometimes fermented. Anaerobic, becoming aerotolerant with subsequent transfers. Viability is short aerobically and several months anaerobi- cally. Optimum temperature, between 36° and 38° C. No growth below 22° C. Optimum pH, between 6.0 and 8.5. Pathogenicity: Most strains are not pathogenic; some produce slight local swell- ing subcutaneously with little pus in guinea pigs and mice. Distinctive characters: Growth in alter- nate zones in agar; strict anaerobe at first, later aerotolerant. Source: Isolated from skin abscesses and from cases of appendicitis, synergistic gangrene and endocarditis. Habitat: Found in the respiratory tract, mouth and vagina. 10. Peptostreptococcus magnus (Pre- vot, 1933) Smith, comb. nov. (Diplococcus magnus anaerobius Tissier and Martelly, Ann. Inst. Past., 16, 1902, 885; Diplococcus magnus Prevot, Ann. Sci. Nat., Ser. Bot., 15, 1933, 140.) mag'nus. L. adj. magnus large. Large spheres, 1.5 to 1.8 microns in di- ameter, usually in pairs, sometimes occur- ring singly, in small clumps or in very short chains. Gram-positive. Gelatin: Growth slow, scant. No lique- faction. Deep agar colonies: After 24 hours at 37° C, lenticular, whitish, granular; margin finely cut. No gas produced. Broth: Turbid, clearing in 4 or 5 days resulting in a viscous mass similar to the zoogloea which Clostridium bifermentans forms. Peptone broth: Slight turbidity; indole not produced. Milk: Unchanged. Carbohydrates not attacked. Fibrin not digested. Sterilized urine : Turbid in 3 to 4 days. The urea is attacked forming (NH4)2C03. Proteoses: Digested and disintegrated forming (NH4)2C03 with the liberation of NH3. Anaerobic.