FAMILY V. BRUCELLACEAE 



415 



Glycerol-agar: Growth non-pigment ed 

 (Thompson, Jour. Bact., 26, 1933, 224). 



Broth: Moderate growth, favored by the 

 addition of serum and peptone. Freshly 

 isolated strains grow in the form of small 

 granules which adhere to the walls of the 

 tube or are collected on its bottom, leaving 

 the broth fairly clear. On the surface, a 

 fine, fragile pellicle is formed. Later genera- 

 tions may grow rather diffusely. No change 

 in reaction of medium. No odor. 



Coagulated serum and Loeffler serum: 

 Good growth. A whitish, opaque laj'er is 

 produced. No proteolysis. 



Litmus milk: Most strains produce no 

 change, some strains produce a slight red- 

 dening after 4 to 6 days. No coagulation. 



Potato: On natural potato, little or no 

 growth; on potato rendered alkaline, a 

 rather feeble, shining and yellowish gray 

 layer may be formed. 



Indole produced in small amounts. 



Hydrogen sulfide not produced. 



Acid but no gas within 48 hours from 

 glucose, maltose, sucrose and mannitol; 

 some strains, after longer incubation, also 

 produce acid from lactose, galactose, raf- 

 finose, glycerol and salicin. No acid within 

 10 days from arabinose, rhamnose, adonitol, 

 dulcitol, inositol, sorbitol or inulin. 



Nitrites not produced from nitrates. 



Aerobic, facultatively anaerobic; primary 

 cultures are microaerophilic. 



Temperature relations: Optimum, 37° C. 

 Slight growth at 20° C. Killed in m hours 

 at 52°, in 1 hour at 54°, in 10 minutes at 

 62° and in 1 minute at 100° C.; on agar 

 slants, survival for 10 to 12 da3's. 



No exotoxin is produced. 



Pathogenic for cattle and swine. A few 

 cases have been reported in man. Rabbits 

 and guinea pigs are slightly susceptible to 

 inoculation. 



Serologically homogeneous (Haupt, Arch, 

 f. wissen. u. prakt. Tierheilk., 67, 1934, 516); 

 related serologically to Actinobacillus mallei 

 Thompson (Thompson, Jour. Bact., 26, 

 1933, 225). 



Source and Habitat: Usually isolated 

 from actinobacillosis of cattle. This condi- 

 tion is often clinically diagnosed as "actino- 

 mycosis". Lesions are found in soft tissues, 

 usually in lymph nodes and in muscles of 



the tongue ("wooden tongue"), where 

 granulomatous tumors are formed. Even- 

 tually these break down to form abscesses, 

 the pus containing small grayish white 

 granules. 



2. Actinobacillus eqiiuli (van Straaten, 

 1918) Haupt, 1934. {Bacillus nephriiidis equi 

 Meyer, Transvaal Dept. Agr. Rept. Gov. 

 Bac, 1908-1909, 122; Bacterium viscosum 

 equi Magnusson, Svensk. Veterinartidskr., 

 1917, 81; also see Jour. Comp. Path, and 

 Therap., 32, 1919, 143; Bacillus equuli van 

 Straaten, Verslag van den Werksaamheden 

 der Rijksseruminrichting voor 1916-1917, 

 Rotterdam, 1918, 75; Bacillus equirulis, 

 incorrectly attributed to van Straaten by 

 de Blieck and van Heelsbergen, Tijdschr. v. 

 Diergeneesk., 46, 1919, 496; Bacterium 

 pyosepticum viscosum Miessner, Deutsch. 

 tierarztl. Wochnschr., 29, 1921, 185; Shigella 

 equirulis Edwards, Kentucky Agr. Exp. 

 Sta. Res. Bui. 320, 1931; Haupt, Arch. f. 

 wissen. u. prakt. Tierheilk., 67, 1934, 514.) 



e.quu'li. L. noun eguulus a small young 

 horse, a foal; L. gen. noun equuli of a foal. 



Description taken largely from Edwards 

 {op. cit., 1931). 



Rods, 0.3 to 0.4 by 0.5 to 0.8 micron, 

 occurring singly, in chains and in filaments. 

 The prevailing forms in rough, mucoid 

 colonies are short, oval rods, and in smooth, 

 non-mucoid colonies, long filaments and 

 chains prevail. Capsules have been de- 

 scribed, but their existence is uncertain. 

 Non-motile. Gram-negative. 



Gelatin colonies : Similar to those on agar. 

 No liquefaction. 



Agar slant: Grayish white, viscid growth 

 covering the surface. Viable 8 to 10 days. 



Infusion-peptone-agar: Good growth. 

 Colonies 3 to 6 mm in diameter in 48 hours. 

 In primary cultures rough type colonies 

 prevail with lobulated surface and mucous 

 or stringy consistency; in later generations 

 smooth type colonies with glistening smooth 

 surface and of soft (non-mucous) consist- 

 ency prevail. 



Broth: Masses are formed on the wall of 

 the tube. At times a thin, grayish pellicle 

 is formed. Grayish, tough, ropy sediment. 

 Eventually there is diffuse turbidity which 

 is highly viscous. Viability, 2 to 4 weeks. 



