FAMILY PARVOBACTERIACEAE 



573 



Egg albumen broth : Albumen not 

 attacked. 



Indole is formed. 



Hydrogen sulfide produced (Eggerth 

 and Gagnon). 



Litmus milk: Acid, coagulated. Curd 

 shrinks with expulsion of turbid whey. 



Nitrates not recorded (Distaso). Ni- 

 trites not produced from nitrates (Eg- 

 gerth and Gagnon). 



Peptone : No gas (Eggerth and Gag- 

 non). 



Acid and gas from esculin, amygdalin, 

 arabinose, fructose, inulin, lactose, cello- 

 biose, dextrin, galactose, glucose, glj'co- 

 gen, maltose, mannose, melezitose, 

 raflinose, rhamnose, salicin, starch, su- 

 crose, trehalose and xylose. Four strains 

 fail to produce gas from any sugar. No 

 acid or gas from glycerol, mannitol or 

 sorbitol (Eggerth and Gagnon). 



Anaerobic . 



Distinctive characters : Resembles 

 Bncteroides variabilis but is not cap- 

 sulated, does not liquefy gelatin, usually 

 forms gas from sugars, and ferments 

 melezitose and trehalose. Differs from 

 Bacteroides unifonnis in morphology, 

 forming gas from sugars and in ferment- 

 ing rhamnose (Eggerth and Gagnon). 



Source : Isolated frequently from 

 human feces. 



Habitat : Intestinal canal of mammals 

 (common ) . 



20. Bacteroides variabilis (Distaso) 

 Castellani and Chalmers. {Bacillus 

 variabilis Distaso, Cent. f. Bakt., I 

 Abt., Orig., 62, 1912, 441; Castellani and 

 Chalmers, jVIan. Trop. Med., 3rd ed., 

 1919, 960; Capsularis variabilis Prevot, 

 Ann. Inst. Past., ffO, 1938, 293.) From 

 Latin variabilis, variable. 



Short rods, with rounded ends, occur- 

 ring singly. Some long flexuous rods. 

 Capsulated. Non-motile. Gram- 



negative . 



Gelatin: No growth on plain gelatin 

 (Distaso); liquefaction (Eggerth and 

 Gagnon, Jour. Bact., 25, 1933, 400). 



Blood agar colonies : Smooth, glistening, 

 elevated and ver^' mucoid, about 1.0 

 mm in diameter. 



Broth: Diffuse growth. 



Indole is formed. 



Hj-drogen sulfide is formed. 



Litmus milk: Unchanged (Distaso); 

 acidified and some strains coagulating 

 in 25 to 35 days (Eggerth and Gagnon). 



Nitrites not produced from nitrates 

 (Eggerth and Gagnon). 



Peptone : No gas. 



Acid and gas from glucose, lactose and 

 sucrose (Distaso) . Acid and no gas from 

 esculin. amygdalin, arabinose, cello- 

 biose, dextrin, fructose, galactose, 

 glycogen, inulin, lactose, glucose, 

 maltose, mannose, raffinose, rhamnose, 

 salacin. starch, sucrose and .xylose. 

 No acid or gas from glycerol, mannitol, 

 melezitose, sorbitol or trehalose (Eg- 

 gerth and Gagnon). 



Non-pathogenic for white mice and 

 rabbits. 



Anaerobic. 



Optimum temperature 37°C. 



Distinctive characters: Capsulated. 



Source : Isolated from human feces by 

 Distaso, and by Eggerth and Gagnon 

 (8 strains). 



Habitat : Probably intestinal canal of 

 mammals. 



21. Bacteroides gulosus Eggerth and 

 Gagnon. (Eggerth and Gagnon, Jour. 

 Bact., 2-5, 1933, 398; Spherophoriis gulosus 

 Prevot, Ann. Inst. Past., 60, 1938, 298.) 

 From Latin gulosus, gluttonous. 



Small oval rods: 0.8 to 1.0 by 1.0 to 2.0 

 microns, staining deeper around periph- 

 ery. Non-motile. Gram-negative. 



Gelatin: Liquefied in 2 to 3 weeks. 



Blood agar colonies: Soft, gray, entire, 

 elevated, 2 mm in diameter. 



Broth: Heavy and diffuse growth. 



Indole formed. 



Hj'drogen sulfide is formed. 



Milk : Acidified and coagulated in 4 to 

 20 days. 



Nitrites not produced from nitrates. 



