744 



ORDER V. ACTINOMYCETALES 



are frequently short, rarely exceeding 20 

 microns in length. Gram-positive. 



Best growth is obtained in an atmosphere 

 of low oxygen tension. 



Gelatin: No liquefaction. 



Agar colonies: Dull, whitish granules 

 adhering slightly to the medium. 



Liquid media: A sediment of white gran- 

 ules is produced. 



LoefBer's blood serum: In 4 to 5 days the 

 surface is covered with white granules which 

 are the size of a pin head. 



Serum media: No proteolytic action. 



Brain extract favors growth in some 

 media. 



Indole production slight. 



Acid from glucose, sucrose and starch. 



Anaerobic to microaerophilic. 



Optimum temperature, 37° C. 



Pathogenic when inoculated into dogs, 



rabbits and guinea pigs where it forms sub- 

 cutaneous abscesses. 



Distinctive characters: For some j^ears 

 this organism was regarded as identical with 

 Actinomyces israelii. However, recent work 

 by Brion et al. (loc. cit.), Brion (op. cit., 91, 

 1942, 157), Prevot et al. {op. cit., 81, 1951, 

 85) and Guyard (Thesis, Fac. de Med. et de 

 Pharm. de Lyon, No. 34, Annee Scolaire 

 1951-1952) has shown that these two or- 

 ganisms can be differentiated as follows: 

 A. israelii is pathogenic for man and cattle, 

 and the club-shaped bodies at the ends of 

 the hyphae in the pus granules stain with 

 acid stains while those found in A. baudetii 

 absorb basic stains. 



Source: Isolated from various types of 

 lesions in cats and dogs. 



Habitat: Cause of actinomycosis in cats 

 and dogs. 



FAMILY III. STREPTOMYCETACEAE WAKSMAN AND HENRICI, 1943.* 

 (Jour. Bact., 46, 1943, 339.) 



Strep.to.my.ce.ta'ce.ae. M.L. mas.n. Streptomyces type genus of the family; -aceae 

 ending to denote a family; M.L. fem.pl.n. Streptmnycetaceae the Streptomyces family. 



Vegetative mycelium does not fragment into bacillarj^ or coccoid forms. Conidia borne on 

 sporophores. Primarilj^ soil forms, sometimes thermophilic in rotting manure. A few species 

 are parasitic. 



Key to the genera of family Streptomycetaceae. 



I. Conidia produced in aerial hyphae in chains. 



Genus I. Streptomyces, p. 744. 

 II. Conidia produced terminally and singly on short conidiophores. 



A. No growth between 50° and 65°C. 



Genus II. Micromonospora, p. 822. 



B. Growth occurs between 50° and 65°C. 



Genus III. Thermoactinomyces, p. 824. 



Genus I. Streptomyces Waksman and Henrici, 1943. 



(Streptothrix Cohn, Beitr. zur Biol, der Pflanzen, I, Heft 3, 1875, 186; not Streptothrix Corda, 

 Prachtflora Europaescher Schimmelbildung, 1839; Waksman and Henrici, 

 Jour. Bact., 46, 1943, 339.) 



Strep. to. my 'ces. Gr. adj. streptus pliant, bent; Gr. noun myces fungus; M.L. mas.n. 

 Streptomyces pliant fungus. 



Grow in the form of a much-branched mycelium with a typical aerial mycelium. Conidio- 



* Completely revised by Prof. S. A. Waksman, Rutgers University, New Brunswick, New 

 Jersey, March, 1953. 



