and in mice (Valine and Gaillard, Ann. Inst. Past., 84, 1953,647). Habitat: Found in human cases of actino- mycosis either alone or in mixture with the Gram-positive bacilli of Wolff and Israel (1891). 4. Actinobacillus actinoides (Smith, 1918) Topley and Wilson, 1931. (Bacillus actinoides Th. Smith, Jour. Exp. Med., ^8, 1918, 342; Topley and Wilson, Princip. of Bact. and Immun., 1st ed., 1, 1931, 253 and 256.) ac.ti.no.i'des. Or. noun aciis, actinis a ray; Gr. noun eidus shape, form; M.L. adj. actinoides ray -like. In tissues the organisms appear as delicate rods, 0.4 to 0.5 micron in width, arranged in groups. In cultures, coccoid or bacillary forms occur. In the condensation water of coagulated blood serum, small, round, mulberry-like flakes up to 1 mm in diameter may be seen which consist of sheathed fila- ments, each filament terminating in club- like expansions. The sheaths as well as the clubs are unstainable and enclose chains of minute bacilli. Cells from cultures on agar containing tissue, milk or blood appear in the form of rods without capsules or clubs. Non-motile. Gram-negative. Nutrient agar with or without blood: Uncertain growth. Serial transfers on this medium generally fail. Broth: No growth. Potato: No growth. Litmus milk: No growth. An accumulation of fatty substances in the cultures has been reported. Optimum temperature, 37° C. Not pathogenic for laboratory animals. Distinctive characters: For isolation bits of tissue are brought into the condensation water of coagulated serum, the tubes being sealed with wax. Serial transfers may be successful on the same medium held under increased CO2 tension (microaerophilic con- ditions). Appearance of mulberry-like granules. Relationship to other species: A resem- blance between Actinobacillus actinoides Topley and Wilson and Streptobacillus moniliformis Levaditi et al. has been noted by Dienes and Edsall (Proc. Soc. Exp. Biol., N. Y., 36, 1937, 740); however, in view of its inability to infect laboratory animals and because of its bacillary morphology in calf lungs, Topley and Wilson (Princip. of Bact. and Immun., 3rd ed., 1946, 393) feel that A. actinoides should be treated sepa- rately from S. moniliformis. Comments: Heilmann (Jour. Inf. Dis., 69, 1941, 32) discusses the question raised by Klieneberger (Jour. Path, and Bact., 40, 1935, 93; also see ibid., 4^, 1936, 587), Daw- son and Hobby (Proc. 3rd Intern. Cong, of Microb., New York, 1939, 177) and others on Asterococcus-like forms originating from cultures of Streptobacillus moniliformis Levaditi et al. Source: Isolated by Th. Smith from an enzootic of chronic pneumonia in calves; in five cases the only cultivable organism, in four cases associated with other patho- genic species and in three cases absent. Th. Smith raises the question of some noncul- tivable, unrecognized microorganism. No other authors have observed similar cases. Jones has isolated an organism resembling Actinobacillus actinoides Topley and Wilson from a pneumonia in old white rats (Jour. Exp. Med., 38, 1922, 441). Habitat: Pathogenic, affecting calves and probably other domestic animals. 5. Actinobacillus mallei (Zopf, 1885) Thompson, 1933. (Rotz-Bacillus, Loefl[ler and Schiitz, in Struck, Deutsch. med. Wochnschr., 8, 1882, 707; Bacillus mallei Zopf, Die Spaltpilze, 3 Aufl., 1885, 89; Pfeifferella mallei Buchanan, Jour. Bact., 3, 1918, 54 (type species of genus Pfeifferella Buchanan, loc. cit.) ; Thompson, Jour. Bact., 26, 1933, 226; see ibid., 25, 1933, 44; Malleo- rnyces mallei Pribram, Klassifikation der Schizomyceten, Leipzig und Wien, 1933, 93 (type species of genus Malleomyces Pribram, loc. cit.).) mal'le.i. L. noun malleus the disease glanders; L. gen. noun mallei of glanders. Common name: Glanders bacillus. Description taken largely from Kelser (Man. Vet. Bact., 4th ed., 1943, 325). Slender rods, 0.3 to 0.5 by 1.5 to 4.0 mi- crons, with rounded ends, usually occurring singly, in pairs and in groups; in culture preparations, sometimes occur as filaments.
