566 



MANUAL OF DETERMINATIVE BACTERIOLOGY 



1. Bacteroides fragilis (Veillon and 

 Zuber) Castellani and Chalmers. 

 (Bacillus fragilis Veillon and Zuber, 

 Arch. Med. Exp. et Anat. Path., 10, 

 1898, 870; Castellani and Chalmers, 

 Man. Trop. Med., 3rd ed., 1919, 959; 

 Fusijormis fragilis Topley and Wilson, 

 Princip. Bact. and Immun., 1st ed., 1, 

 1931, 302; Ristella fragilis Prevot, Ann. 

 Inst. Past., 60, 1938, 290.) From Latin 

 fragilis, fragile. 



Rods with rounded ends, staining more 

 deeply at the poles, occurring singly 

 and in pairs. Non-motile. Gram- 

 negative. 



Gelatin : No liquefaction ; small amount 

 of gas. 



Agar colonies: Small, graj^ irregular. 



Broth: Turbid. 



Indole not formed. 



Hydrogen sulfide not formed. 



Litmus milk: No coagulation. Slight 

 amount of gas. 



Nitrites not produced from nitrates. 



Acid from fructose, maltose, sucrose, 

 galactose, glucose and arabinose. Some 

 strains produce acid from lactose (Wein- 

 berg et al., Les Microbes Ana^robies, 

 1937, 720). 



Anaerobic. 



Optimum temperature 37 °C. 



Pathogenicity: Some strains produce 

 subcutaneous abscesses in rabbits, guinea 

 pigs or mice. 



Source and habitat : From acute appen- 

 dicitis, pulmonary gangrene, abscesses 

 of the urinary tract, and septicaemias in 

 man. 



2. Bacteroides serpens (Veillon and 

 Zuber) Hauduroy et al. {Bacillus serpejis 

 Veillon and Zuber, Arch. Med. Exp. et 

 Anat. Path., 10, 1898, 870; Bacillus 

 radiiformis Rist and Guillemot, Arch. 

 Mdd. Exp. et Anat. Path., 1904; Haudu- 

 roy et al.. Diet. d. Bact. Path., 1937, 74; 

 Zuherella serpens Prevot, Ann. Inst. 

 Past., 60, 1938, 293.) From Latin ser- 

 pens, creeping. 



Rods : Thick, with rounded ends, oc- 



curring singly, in pairs, or in short chains. 

 Motile. Gram-negative. 



Gelatin: Slow liquefaction, with gas. 



Agar colonies: Punctiform. 



Deep agar colonies: Small colonies in 

 48 hours, ray-like growth later. Gas 

 produced. 



Broth : Turbid, then flocculent growth ; 

 some gas with foul odor. 



Hj'drogen sulfide not formed. 



Litmus milk: Acidified and coagulated 

 in six daj'S, with no digestion. 



Acid from fructose, galactose, maltose 

 and lactose. 



Coagulated egg white and serum not 

 liquefied. 



Anaerobic. 



Optimum temperature 37°C. 



Experimental pathogenicity : Some 

 strains produce abscesses in rabbits, 

 guinea pigs and mice. 



Source and habitat : Acute appendi- 

 citis, mastoiditis, pulmonary gangrene, 

 l)ile tract of dog, and sea water. 



3. Bacteroides funduliformis (Halle) 

 Bergey et al. {Bacilhis funduliformis 

 Hall^, Inaug. Diss., Paris, 1898; Bacillus 

 thetoides Rist, The«e de Paris, 1898; 

 Bergey et al., Manual, 3rd ed., 1930, 373; 

 Spherophorus funduliformis Prevot, Ann. 

 Inst. Past., 60, 1938, 298.) From Latin 

 funduliformis, sausage -shaped . 



Rods: 1.5 to 3.0 microns long in pus, 

 often spindle-shaped. Extremely pleo- 

 morphic in culture media, showing irreg- 

 ular filamentous and branching forms. 

 Non-motile. Gram-negative. 



Gelatin: Not liquefied. 



Deep agar colonies: Lenticular, with 

 some gas and foul odor. 



Broth: Flocculent growth. 



Glucose broth : Rapid growth with gas 

 and foul odor. 



Indole not formed; although sometimes 

 found in old cultures. 



Hydrogen sulfide is formed in small 

 amounts . 



Litmus milk : Acid and coagulation by 

 some strains. 



