Waksman — 24 — Actinomycetes 



show little biochemical activity. They do not produce soluble pig- 

 ments on protein media or insoluble pigments in their growth; they have 

 no proteolytic action on egg- or serum-containing media; they do not usu- 

 ally clot and do not peptonize milk, and in fact, rarely grow on it at all; 

 they seldom grow on gelatin, and when there is a little flaky growth the 

 tubes when cooled (from the 37°C. necessary for incubation) are found 

 not to have been liquefied; and they have little or no haemolytic action 

 on blood broth or blood agar. Acid is formed from certain sugars: ac- 

 cording to Slack (403) from glucose, maltose, mannitol, sucrose, and 

 lactose; according to Negroni and Bonfiglioli (318) from glucose, 

 galactose, lactose, fructose, maltose, affinose, sucrose, and xylose. Milk 

 also becomes acid. 



Compared with the human strains, the strains of bovine origin dis- 

 play, according to Erickson (113), cultural and morphological differ- 

 ences. Their colonies are smoother and softer in consistency and are not 

 adherent to the medium. Growth is scantier. The mycelium under- 

 goes fragmentation very rapidly, and extensive ramification is rare. No 

 aerial h}'phae have been found. A much greater degree of uniformity is 

 evident in colony development. Occasional turbidity occurs in liquid 

 media. These strains also show a lesser ability to ferment sugars. 

 Source: Jaw of cattle, udder of swine, and man (dental scum, tonsilar 

 crypts)< 



Further information on the morpholog)' and phvsiology of this organ- 

 ism is given later (p. 43). 



In the latest edition of Bergey's Manual, a second species is recog- 

 nized, namely A. israeli, which occurs in human tissues and is said to be 

 responsible for human actinomycotic infections. 



Genus II. Nocardia Trevisan 



^Actinomyces Gasperini, Schottmiiller, Henrici and Gardner; Cohnistrepto- 

 thrix Orskov; Streptotlirix Kruse, Caminiti, Rossi-Doria, Silberschmidt; Cladothrix 

 Eppinger; Brevistreptothrix Lignieres; Actinohacteriuni Haas; Actinocladothrix 

 Afanassiev; Actinohacille Lignieres and Spitz; Actinococcus Beijerinck; Mycococcus 

 Bokor; Asteroides Puntoni and Leonardi; Proactinomyces Jensen.) 



Slender filaments or rods, frequently swollen and occasionally 

 branched, forming mycelium which after reaching a certain size may 

 give the appearance of bacterial growths. Shorter rods and coccoid 

 forms are found in older cultures. Conidia not formed. The nocardias 

 stain readily, occasionally showing a slight degree of acid-fastness. 

 Aerobic. Gram-positive. The colonies are similar in gross appearance 

 to those of the genus Mycohacterhnn. Paraffin, phenol, and m-cresol 

 are frequently utilized as sources of energy. 



In their early stages of growth on culture media (liquid or solid), 

 the structure of a nocardia is similar to that of a streptomyces. Both 

 form a typical mycelium: h)q3hae branch abundantly, the branching 

 being true. The hyphae vary in diameter between 2.5[x and 1[k, most of 



