FAMILY PARVOBACTERIACEAE 



569 



Bipolar staining. Non-motile. Gram- 

 negative. 



Gelatin: Liquefied in 8 to 25 days. 



Blood agar colonies : Very minute and 

 transparent. 



Broth : Diffusely clouded. 



Indole not formed. 



Hydrogen sulfide not produced. 



Milk: Neither acidified nor coagulated. 



Nitrites not produced from nitrates. 



Peptone : No gas. 



Acid but no gas from cellobiose (in 30 

 days), dextrin, glucose, maltose, man- 

 nose and rhamnose. No acid or gas from 

 esculin, amygdalin, arabinose, galactose, 

 mannitol, melezitose, raffinose, salicin, 

 sorbitol, starch, sucrose, trehalose, xylose, 

 glycerol, glycogen, inulin, lactose or 

 fructose. 



Non-pathogenic for white mice and 

 rabbits. 



Anaerobic. 



Source : One strain isolated from hu- 

 man feces. 



Habitat : Probably intestinal canal of 

 mammals. 



10. Bacteroides exiguus Eggerth and 

 Gagnon. (Eggerth and Gagnon, Jour. 

 Bact., 25, 1933, 407; Ristclla exigua Prd- 

 vot, Ann. Inst. Past., 60, 1938, 292.) 

 From Latin 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: Liquefied 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, 1.0 to 1.5 mm 

 in diameter. 



Broth: Diffusely clouded. 



Indole not formed. 



Hydrogen sulfide not formed. 



Milk : Acidified and may or may not be 

 coagulated in 35 to 40 days. 



Nitrites not produced from nitrates. 



Peptone : No gas. 



Acid but no gas from fructose, galac- 

 tose, glucose, lactose, maltose, mannose, 

 sucrose and trehalose. One strain fer- 



ments raffinose. No acid or gas from 

 esculin, amygdalin, arabinose, cellobiose, 

 dextrin, glycerol, glycogen, inulin, man- 

 nitol, melezitose, rhamnose, salicin, sor- 

 bitol, starch or xylose. 



Non-pathogenic for white mice and 

 rabbits. 



Anaerobic. 



Source : Two strains isolated from 

 human feces. 



Habitat : Probably intestinal canal of 

 mammals. 



11. Bacteroides uncatus Eggerth and 

 Gagnon. (Eggerth and Gagnon, Jour. 

 Bact., 25, 1933, 404; Ristella uncata 

 Pr^vot, Ann. Inst. Past., 60, 1938, 

 291.) From Latin uncatus, hooked at 

 the tip. 



Rods : Extreme variations in size and 

 form. The ordinary length is 5.0 to 8.0 

 microns. Curved and hooked forms 

 common. Non-motile. Gram-negative. 



Gelatin: Liquefied in 16 days. 



Blood agar colonies : Very minute and 

 transparent. 



Broth: Turbid, growth is slow and 

 light. 



Indole not formed. 



Hydrogen sulfide not formed. 



Milk : Not acidified or coagulated. 



Nitrites not produced from nitrates. 



Peptone : No gas. 



Acid but no gas after 8 to 30 days of 

 incubation from dextrin, fructose, galac- 

 tose, glucose, lactose, maltose, raffinose, 

 rhamnose, salicin, starch and sucrose. 

 No acid from esculin, amygdalin, arabi- 

 nose, cellobiose, glycerol, glycogen, in- 

 ulin, mannitol, mannose, melezitose, 

 sorbitol, trehalose or xylose. 



Non-pathogenic for white mice and 

 rabbits. 



Anaerobic. 



Source : One strain isolated from human 

 feces. 



Habitat : Probably intestinal canal of 

 mammals. 



12. Bacteroides vulgatus Eggerth and 

 Gagnon. (Eggerth and Gagnon, Jour. 



