Differential Characters of THE Three Species of Genus Brucella. Infec- tivity for Guinea Pigs (a), 30 Days Re- quires CO2 for Isola- tion, 5 Per Cent HjS Forma- tion, 4 Days Urease Acti- vity, 4hr. Cata- lase Acti- vity, 30Min. Growth in tlie Presence of Sugar Fermentation (c) Species (a) c .2 8
+
+
+
1
+ + + 1
+
+
+
+
1
+ ± ±
Si
1 Brucella melitensis type I ++++
-, ± -, ++ ++ ++++ ++++ + + -1- -t- + + +
++++ ++++ ++++ ++ ++ ++ ++ ++ ++ -, ++ -, ++ -, + + + -1- +
++++
++++
++++ n
Brucella abortus type III
++++ ++++ ++++
++++ -, ± ++++ ++++ ++++ ++++ ++++ ++++ ++++ ++++ ++++
++++
-1-
+
+
(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.
