Page:Bergey's manual of determinative bacteriology.djvu/454

 ex.i'gu.us. L. adj. exiguus small and narrow. Very small, slender rods, 0.5 to 1.0 micron long, occurring singly and in pairs. Non- motile. Gram-negative. Gelatin: Liquefaction in 16 to 20 days. Blood agar colonies: These are of two types: one is pin-point in size, the other is large, gray, moist and 1.0 to 1.5 mm in diameter. Broth: Diffusely clouded. Milk: Acidified and may or may not be coagulated in 35 to 40 days. Indole not produced. Hydrogen sulfide not produced. Acid but no gas from fructose, galactose, glucose, lactose, maltose, mannose, sucrose and trehalose. One strain ferments raffinose. No acid or gas from esculin, amygdalin, arabinose, cellobiose, dextrin, glycerol, glycogen, inulin, mannitol, melezitose, rhamnose, salicin, sorbitol, starch or xylose. Nitrites not produced from nitrates. Peptone: No gas. Anaerobic. Non-pathogenic for white mice or rabbits. Source: Two strains were isolated from human feces. Habitat: Probably the intestinal canals of mammals. 19. Bacteroides uniformis Eggerth and Gagnon, 1933. (Eggerth and Gagnon, Jour. Bact., 25, 1933, 400; Rislella uniformis Pr^vot, Ann. Inst. Past., 60, 1938, 291.) u.ni.for'mis. L. adj. uniformis of a single form. Small rods, 0.8 to 1.5 microns long, with rounded ends, occurring singly. Non-motile. Stain heavier at poles and around periphery. Gram-negative. Gelatin: Liquefaction by two strains in 15 to 40 days. No liquefaction by six strains. Blood agar colonies: Transparent, soft, elevated, 0.5 to 0.75 mm in diameter. Broth: Diffuse growth. Milk: Acidified and coagulated in 8 to 12 days. Indole is produced. Hydrogen sulfide produced slowly or not at all. Acid but no gas from esculin, amygdalin, arabinose, cellobiose, dextrin, fructose, galactose, glucose, glycogen, inulin, lactose, maltose, mannose, melezitose, raffinose, salicin, starch, sucrose, trehalose and xylose. No acid or gas from glycerol, manni- tol, rhamnose, sorbitol, dulcitol, erythritol or inositol. Nitrites not produced from nitrates. Peptone: No gas. Anaerobic. Non-pathogenic for white mice or rabbits. Distinctive characters: Produces indole. Resembles Bacteroides vulgatus. Source: Eight strains were isolated from human feces. Habitat: Probably the intestinal canals of mammals. 20. Bacteroides vulgatus Eggerth and Gagnon, 1933. (Eggerth and Gagnon, Jour. Bact., 25, 1933, 401; Pasteurella vulgata Prevot, Ann. Inst. Past., 60, 1938, 292.) vul.ga'tus. L. adj. vulgatus common. Ellipsoidal rods, 0.7 to 2.5 microns long, usually occurring singly, sometimes in pairs; one strain forms filaments 10.0 microns long. Morphology very variable in glucose broth. Non-motile. Stain solidly, although some strains show bipolar staining. Gram-nega- tive. Gelatin: Liquefaction in 4 to 20 days by all but one strain. Blood agar colonies: Soft, translucent, grayish, elevated, 1.5 to 2.0 mm in diam- eter. Half of the strains are hemolytic. Broth: Heavy and diffuse growth. Milk: Acidified. Coagulated by some strains in 5 to 25 days. Indole not produced. Hydrogen sulfide is produced. Acid and a small amount of gas from arabinose, dextrin, fructose, galactose, glucose, glycogen, inulin, lactose, maltose, mannose, raffinose, rhamnose, starch, su- crose and xylose. Seven strains fermented esculin. No acid or gas from amygdalin, cellobiose, glycerol, mannitol, melezitose, salicin, sorbitol, trehalose, dulcitol, erythri- tol or inositol. Nitrites not produced from nitrates. Anaerobic. Non-pathogenic for white mice or rabbits. Distinctive characters: Does not form indole; does not produce gas from peptone.