FAMILY PARVOBACTERIACEAE 



561 



Past., 7, April, 1893, 289; Hughes, La 

 Riforma Med., S, Aug. or Sept., 1893, 

 789 and Ann. Inst. Past., 7, Aug., 1893, 

 630; BacteriiDu melitense Ssiisawsi, Ztschr. 

 f. Hyg., 70, 1912, 181; Meyer and Shaw, 

 Jour. Inf. Dis., 27, 1920, 173; Bacillus 

 melitensis Holland, Jour. Bact., 5, 1920, 

 219; Alcaligenes melitensis Bergey et al.. 

 Manual, 1st ed., 1923, 235; Brucella meli- 

 tensis var. melitensis Evans, U. S. Public 

 Health Reports, 38, 1923, 1947.) From 

 Latin, of Malta. 



Short ellipsoidal rods : 0.3 to 0.4 micron 

 in length, occurring singly and in pairs, 

 rarely in short chains. Non-motile. 

 Non-acid-fast. Gram-negative. 



Gelatin colonies: Small, clear, entire. 



Gelatin stab: Slow growth. No lique- 

 faction. 



Agar colonies: Small, circular, convex, 

 amorphous, smooth, glistening, entire, 

 bluish-green, grayish if R type. 



Agar slant : Growth slow, moist, honey- 

 like, entire. After a week, the agar is 

 turned brownish and crystals may ap- 

 pear. 



Broth: After 10 days, moderate turbid- 

 ity and grayish sediment. Reaction al- 

 kaline, pH 8.0 or higher. 



Litmus milk: LTnchanged at 24 hours. 

 Later becomes alkaline. 



Potato: Scant growth, grayish becom- 

 ing brownish. 



Indole not formed. 



Nitrates reduced, often with complete 

 disappearance of nitrite (Zobell and 

 Meyer, Jour. Inf. Dis., 51. 1932, 99). 

 Because of the latter fact, reports in the 

 literature are apparently contradictor}'. 



Ammonia produced from urea. 



Growth enhanced on beef liver or 

 tryptose agar of pH 6.8. 



Neither acid nor gas from carbohydrate 

 media. 



Optimum reaction pH 7.4. 



Optimum temperature 37°C. No 

 growth at 6° or at 45°C. Killed at 59°C. 



Aerobic. 



Distinctive characters : Requires no 

 increased COo tension. 



Source : Isolated by Bruce (1887, loc. 

 cit.) from the spleen in fatal cases of 

 Malta fever. 



Habitat: Chief host the milch goat. 

 The cause of undulant fever (brucellosis) 

 in man and abortion in goats. IMay in- 

 fect cows and hogs and be excreted in 

 their milk. Infectious for all domestic 

 animals. 



2. Brucella abortus (Schmidt and 

 Weis) Meyer and Shaw. (Bacillus of 

 abortion. Bang, Ztschr. f. Thiermed., 1, 

 1897, 241 ; Bacterium abortus Schmidt 

 and Weis, Bakterierne, 1901, 266; Bac- 

 terium abortivum Chester, Man. Determ. 

 Bact., 1901, 121 ; Corynebacterium abortus 

 endemici Preisz, Cent. f. Bakt., I Abt., 

 Orig., 33, 1902, 194; Bacillus abortus 

 Evans, Jour. Wash. Acad. Sci., 5, 1915, 

 122; Meyer and Shaw, Jour. Inf. Dis., 

 27, 1920, 173; Alcaligenes abortus Bergey 

 etal., Manual, 1st ed., 1923, 234; Brucella 

 melitensis var. abortus Evans, Public 

 Health Reports, 38, 1923, 1947.) From 

 Latin abortus, an untimely birth. 



The morphological and cultural charac- 

 ters are similar to those of Brucella 

 melitensis with the following exceptions : 

 Requires 10 per cent CO2 for isolation, 

 becomes aerobic after several transfers; 

 the browning of the medium in agar slant 

 culture is less marked; S cultures can be 

 difl'erentiated from Brucella melitensis, 

 but not from Brucella suis, by the ag- 

 glutinin absorption test. 



Source : From the genital organs and 

 milk of infected cattle and from blood in 

 human cases of undulant fever. 



Habitat: Chief host the milch cow. 

 The cause of infectious abortion in cattle. 

 The same effects are produced in mares, 

 sheep, rabbits and guinea pigs, and all 

 domestic animals except hogs. Causes 

 undulant fever (brucellosis) in man. 



3. Brucella suis Huddleson. (Organ- 

 ism resembling Bacillus abortus. Anony- 

 mous, U. S. D. A. Ann. Rept. Secy. 

 Dept., Rept. of Chief Bur. Animal Ind., 



