FAMILY V. BRUCELLACEAE 



405 



(a) TypeS, primary isolation; (b) Final cone, 10"'; (c) Pickett and Nelson (Jour. Bact., 69, 1955, 333). 



Brucella melitensis. As indicated in the table, cultures of this species show some variation in characteristics. These 

 variations, in turn, show some relationship to geographical distribution and/or to the host animal. The cultures de- 

 scribed under I appear to be most typical of the species (Folding, Indian Jour. Vet. Res., 27, 1950, 170). 



Brucella abortus. The cultures described in the table under I are regarded as possessing the characteristics that are 

 most typical for the species. The cultures described under II were first described by Wilson (Jour, of Hyg., 4, 1933, 

 516) from cattle in France. Cultures showing the characters under III appear to come mainly from Asian countries 

 (Indonesia, India, Iran, Turkey). Wilson and Miles (in Topley and Wilson, Princip. Bact. and Immun., 3rd ed., /, 

 1946, 820) record similar cultures from Southern Rhodesia. 



Brucella suis. The cultures described in the table under I are regarded as typical of the species. Those described 

 under II are representative of the Thomson strain. Wilson and Miles {ibid., 821) state that Br. suis strains from Den- 

 mark are more susceptible to all dyes than strains from America, although their differential susceptibility is the 

 same. Those described under type III are representative of cultures isolated largely since 1949 from man and hogs 

 from the hog-raising areas of central United States. 



1. Brucella melitensis (Hughes, 1892) 

 Meyer and Shaw, 1920. (Bruce, Practitioner, 

 39, 1887, 161; also see ibid., 40, 1888, 241; 

 and Rept. Army Med. Dept., London, 32, 

 1890, Append. No. 4, 465; streptococcus 

 Miletensis (sic) Hughes, The Mediterranean 

 Naturalist, S, February 1, 1892, 325; Micro- 

 coccus melitensis Bruce, Ann. Inst. Past., 

 7, April, 1893, 289; Hughes, La Riforma 

 Med., 3, Aug. or Sept., 1893, 789; also see 

 Ann. Inst. Past., 7, Aug., 1893, 630; Meyer 

 and Shaw, Jour. Inf. Dis., 27, 1920, 173.) 



me.li.ten'sis. L. adj. melitensis of or 

 pertaining to the Island of Malta. 



Short, ellipsoidal rods, 0.3 to 0.4 micron 

 in length, occurring singly, in pairs and 

 rarely in short chains. Non-motile. Not 

 acid-fast. Gram-negative. 



Gelatin colonies: Small, clear, entire. 



Gelatin stab: Slow growth. No liquefac- 

 tion. 



Agar colonies: Small, circular, convex, 



amorphous, smooth, glistening, entire, 

 bluish green, grayish if R type. 



Agar slant: Growth moist, honey-like, 

 entire. After a week the agar is turned 

 brownish and crystals may appear. 



Broth: After 10 days, moderately turbid 

 with grayish sediment. Reaction alkaline; 

 pH 8.0 or higher. 



Litmus milk: Unchanged at 24 hours; 

 later becomes alkaline. 



Potato: Scant, grayish growth becoming 

 brownish. 



Growth enhanced on peptone media of 

 pH 7.0. 



Indole not produced. 



Glucose is fermented. 



Nitrites produced from nitrates, often 

 with complete disappearance of the nitrite 

 (ZoBell and Meyer, Jour. Inf. Dis., 61, 

 1932, 99). Because of the latter fact, reports 

 in the literature are apparently contradic- 

 tory. 



