742 



ORDER V. ACTINOMYCETALES 



Genus II. Actinomyces Harz, 1877. 



(Harz, in Bollinger, Cent. f. med. Wissensch., 15, 1877, 485; also see Jahresber. d. Munch. 



Thierarzeneischule fiir 1877-78, 1879, 125; not Actinomyce Meyen, Linnaea, £, 1827, 442; 



Cohnistreptothrix Pinoy (in part), 1911, see Pinoy, Bull. Inst. Past., 11, 1913, 929.) 



Ac.ti.no.my'ces. Gr. noun actis, actinis ray; Gr. noun myces fungus; M.L. mas.n. Ac- 

 tinomyces ray-fungus. 



True mycelium produced. The vegetative mycelium fragments into elements of irregular 

 sizes and may exhibit angular branching. No conidia produced. Not acid-fast. Anaerobic 

 to microaerophilic. Pathogenic for man and other animals. 



The type species is Actinomyces hovis Harz. 



Key to the species of genus Actinomyces. 



I. Colonies soft, smooth, uniform, not adherent to medium. No aerial hyphae. 



1. Actinomyces hovis. 



II. Colonies tough in texture and warted in appearance, adherent to medium. Scant aerial 

 growth of hyphae. 



A. Hyphae in pus granules stain with acid stains. 



2. Actinomyces israelii. 



B. Hyphae in pus granules stain with basic stains. 



3. Actinomyces baudetii. 



1. Actinomyces bovis Harz, 1877. (Harz, 

 in Bollinger, Cent. f. med. Wissensch., 15, 

 1877, 485; also see Jahresber. d. Mlinch. 

 Thierarzeneischule fiir 1877-78, 1879, 781.) 



bo'vis. L. noun 60s the ox; L. gen. noun 

 bovis of the ox. 



Description taken from Erikson (Med. 

 Res. Council, London, Spec. Rept. Ser. 

 240, 1940, 63 pp.). 



No aerial hyphae. Radiate, sulfur-colored 

 granules occur in the pus found in cases of 

 actinomycosis. Large club-shaped hyphae 

 are seen in morbid tissues. Mycelium under- 

 goes fragmentation very rapidly, extensive 

 branching being rare. Hyphae less than 1 

 micron in diameter. Non-motile. Not acid- 

 fast. Gram-positive. 



Colonies: Smoother and softer in con- 

 sistency and more uniform than those of 

 the following species. The colonies are not 

 adherent to the medium, and growth is 

 scantier. 



Semi-solid media: Excellent growth, 

 especially with paraffin seal. 



Gelatin: Occasionally scant, flaky growth. 

 No liquefaction. 



Liquid media: Occasionally turbid with a 

 light, flocculent growth. 



Acid from glucose, sucrose and maltose. 

 No acid from salicin or mannitol. 



Pigments: No soluble pigments produced 



on protein media. No insoluble pigments 

 produced by growth. 



Egg or serum media: No proteolytic ac- 

 tion. 



Litmus milk: Becomes acid but usually 

 no coagulation, no peptonization. Some- 

 times no growth. 



No hemolysis in blood broth or blood agar. 



Anaerobic to microaerophilic. Bovine 

 strains are more oxygen-tolerant on egg 

 or serum media than strains of human origin 

 belonging to the following species. 



Optimum temperature, 37° C. 



Serology: No cross agglutination between 

 five bovine strains and human strains of 

 Actinomyces israelii. No cross reactions 

 with representative aerobic strains. 



Comments: As pointed out by Lignieres 

 and Spitz (Bull. Soc. cent. M6d. vet., 20, 

 1902, 487 and 546) and others, distinction 

 should be made between the infections pro- 

 duced by Actinomyces bovis and those pro- 

 duced by the Gram-negative Actinobacillus 

 now known as Actinobacillus lignieresii. 

 These infections frequently occur in mixed 

 form and are also frequently complicated 

 by the presence of pj'ogenic cocci (Magnus- 

 sen, Acta path. Microbiol. Scand., 5, 1928, 

 170; and others). 



Relationships to other species: This and 

 the following species are sometimes re- 



