FAMILY VI. BACTEEOIDACEAE 



433 



This is the commonest Bacteroides species 

 found in the feces of adults. Differs from 

 Bacteroides incommunis in that it does not 

 ferment am3'gdalin and cellobiose but does 

 ferment glj^cogen and starch. Liquefies 

 gelatin. 



Source: Thirty-eight strains were iso- 

 lated from human feces. 



Habitat: Probablj' the intestinal canals 

 of mammals. 



21. Bacteroides distasonis Eggerth and 

 Gagnon, 1933. (Eggerth and Gagnon, Jour. 

 Bact., 25, 1933, 403; Ristella distasonis 

 Prevot, Ann. Inst. Past., 60, 1938, 291.) 



dis.ta.so'nis. M.L. gen.noun distasonis of 

 Distaso; named for A. Distaso, a Rouma- 

 nian bacteriologist. 



Rods, 0.5 to 0.8 b}^ 1.5 to 2.5 microns, with 

 rounded ends, occurring singly; some strains 

 show a few bacilli 5.0 to 8.0 microns long. 

 Non-motile. Stain solidly. Gram-negative. 



Gelatin: No liquefaction by 16 strains; 

 liquefaction by the remaining four strains in 

 35 to 50 days. 



Blood agar colonies: Soft, gra3-ish, ele- 

 vated, 1.0 to 1.5 mm in diameter. Two 

 strains are markedly hemolytic. 



Broth: Growth is diffuse. 



Milk: Acidified. All but 4 strains coagu- 

 late milk. 



Indole not produced. 



Hydrogen sulfide is produced. 



Acid but no gas from amygdalin, cello- 

 biose, dextrin, fructose, galactose, glucose, 

 inulin, lactose, maltose, mannose, melezi- 

 tose, raffinose, rhamnose, salicin, sucrose, 

 trehalose and xylose. Fifteen strains fer- 

 ment esculin. Fifteen strains slowly ferment 

 starch. No acid or gas from arabinose, glj'co- 

 gen, glycerol, mannitol or sorbitol. 



Nitrites not produced from nitrates. 



Peptone: No gas. 



Anaerobic. 



Non-pathogenic for white mice or rabbits. 



Distinctive characters: Usually fails to 

 liquefy gelatin. Fails to ferment arabinose. 



Source : Twenty strains were isolated from 

 human feces. 



Habitat: Probably the intestinal canals 

 of mammals. 



22. Bacteroides capillosus (Tissier, 



1908) Kelly, comb. nov. (Bacillus capillosus 

 Tissier, Ann. Inst. Past., 22, 1908, 189; 

 Ristella capillosa Prevot, Ann. Inst. Past., 

 60, 1938, 292.) 



ca.pil.lo'sus. L. adj. capi7Zosws very hairy. 



Long, thick rods, 1 by 4 to 5 microns, 

 occurring singly or in chains; curved and 

 filamentous forms are present, and they may 

 become tangled. Non-motile. Gram-nega- 

 tive. 



Gelatin: No liquefaction. 



Agar: Deep colonies fine, granular, ir- 

 regular, fimbriate. No gas produced. 



Broth: Slight turbidity. 



Milk: Growth but no change. 



Coagulated egg white not digested. 



Indole not produced. 



Hydrogen sulfide not produced. 



Slight acid from glucose. No acid from 

 lactose or sucrose. 



Anaerobic. 



Optimum temperature, 37° C. 



Not pathogenic. 



Source: Isolated twice from the intestines 

 of infants. 



Habitat: Found in the intestinal tract of 

 man. 



23. Bacteroides cylindroides (Rocchi, 

 1908) Kelly, comb. nov. (Bacterium cylin- 

 droides Rocchi, Lo stato actuale delle nostre 

 cognizioni sui germi anaerobi Gamberine e 

 Parmezziani, Bologna, 1908; Ristella cylin- 

 droides Prevot, Ann. Inst. Past., 60, 1938, 

 292.) 



cy.lin.dro.i'des. Gr. noun cylindrus a 

 cjdinder; Gr. noun idus form, shape; M.L. 

 adj. cylindroides cylinder-shaped. 



Large, filamentous rods, 6 to 8 microns 

 long, with granular, swollen areas. Non- 

 motile. Gram-negative. 



Gelatin: No liquefaction. 



Glucose agar: Deep colonies small, round. 



Glucose broth: Turbid with light deposit. 



Milk: Unchanged. 



Albumin not digested. 



Acid from glucose and sucrose. No acid 

 from lactose, galactose, mannitol or dulci- 

 tol. 



Anaerobic. 



Grows only at 18° C. 



Not pathogenic. 



