574 



MANUAL OF DETERMINATIVE BACTERIOLOGY 



Acid and a very small amount of gas 

 from esculin, amygdalin, arabinose, cel- 

 lobiose, dextrin, fructose, galactose, 

 glycogen, inulin, lactose, glucose, mal- 

 tose, mannitol, mannose, melezitose, 

 raffinose, rhamnose, salicin, sorbitol, 

 starch, sucrose, trehalose and xylose. 

 Sorbitol and mannitol require 2 to 3 weeks 

 for fermentation. Neither acid nor gas 

 from glycerol, dulcitol, erj'thritol or 

 inositol. 



Peptone : No gas. 



Non-pathogenic for white mice and 

 rabbits. 



Anaerobic. 



Source : Seven strains isolated from 

 human feces. 



Habitat : Probably intestinal canal of 

 mammals. 



22. Bacteroides melaninogenicus (Oli- 

 ver and Wherry) Roy and Kelly. {Bac- 

 terium melaninogenicum Oliver and 

 Wherry, Jour. Inf. Dis., 28, 1921, 341; 

 Hemophilus melaninogenicus Bergey et 

 al., Manual, 3rd ed., 1930, ZU; Ristella 

 melaninogenica Pr^vot, Ann. Inst. Past., 

 60, 1939, 290; Roy and Kelly, in Manual, 

 5th ed., 1939, 569.) From Greek, black- 

 producing. 



Description taken from Oliver and 

 Wherry {loc. cit.) and Burdon (Jour. 

 Inf. Dis., 42, 1928, 161). 



Rods: 0.8 by 1.0 to 3.0 microns. Non- 

 motile. Gram-negative. 



Serum gelatin stab: Dense flocculent 

 growth at 37°C. No liquefaction. 



Blood agar slant: Confluent, black, 

 dry layer. The blood is disintegrated 

 in one to two weeks forming melanin. 

 The medium becomes colorless. 



Sodium phosphate broth: Turbid. 



Litmus milk : Slow acidification but no 

 coagulation. 



Blood serum slant : Fairly luxuriant, 

 white, moist layer. 



Acid from fructose, glucose, lactose, 

 maltose, sucrose and mannitol. No acid 

 from galactose. 



Non-pathogenic for rabbits, guinea 



pigs and white mice (Burdon). Anaero- 

 bic. 



Optimum temperature 37 °C. 



Distinctive characters : Growth very 

 poor unless fresh body fluids are added 

 to the medium. Grows more readily in 

 mixed culture. When grown on a me- 

 dium containing haemoglobin, a black 

 pigment is produced (melanin). 



Source : Oral cavity, external genitalia, 

 infected surgical wound, urine and 

 feces (Oliver and Wherry). 



Habitat : Inhabits healthy mucous 

 membranes of mammals, but may take a 

 part in various pathological processes 

 (Burdon). 



23. Bacteroides caviae (Vinzent) Hau- 

 duroy et al. (Streptobacillus caviae 

 Vinzent, Ann. Inst. Past., 42, 1928, 533; 

 Hauduroy et al.. Diet. d. Bact. Path., 

 1937, 53; Spherophorus caviae Pr^vot, 

 Ann. Inst. Past., 60, 1938, 299.) From 

 Cavia, a genus of rodents. 



Rods: Small, sometimes curved. 

 Usually 0.3 to 0.5 by 1.0 to 1.5 microns. 

 Occurring singly and in chains. Pleo- 

 morphic in old cultures with long 

 filamentous forms. Non-motile. Gram- 

 negative. 



Serum gelatin : No liquefaction. 



Serum agar: Surface colonies, small, 

 translucent, slightly raised, adherent to 

 medium in 48 hours. Deep colonies, 

 lenticular, 2 mm in size in 48 hours. 

 Colonies difBcult to break up. No gas. 



Serum broth : Supernatant fluid clear, 

 with small, stellate colonies, which tend 

 to adhere to walls of the tube. No gas. 



Indole not formed in serum peptone 

 water. 



Hydrogen sulfide not formed. 



Milk: Unchanged. 



Coagulated egg white and serum not 

 liquefied. 



No acid or gas from carbohydrates. 



Pathogenic for guinea pigs, rabbits and 

 mice. 



Anaerobic. 



Optimum temperature 37 °C. 



