Description of 

 Species of Nocardia 



Next to species of the streptomycetes, the nocardias are known to be the 

 most prolific producers of antibiotics. Although none of these has so far 

 found any practical application, the possibility is not excluded that in 

 time they might be found useful. 



The genus Streptomyces comprises forms producing plant diseases but 

 no animal disease has ever been associated with a true member of this 

 group. The Nocardia group, on the other hand, contains a number of 

 forms known to be associated with animal diseases, or at least to have 

 been isolated from tissues so diseased. This gave origin to a condition 

 known as "nocardiosis." 



In contradistinction to the genus Actinomyces, the Nocardia group is 

 aerobic in nature. The colonies are smooth, rough or folded, usually of a 

 soft or dough-like consistency, but often compact and leathery, especially 

 in early stages of growth. Most species do not produce any aerial mycelium. 

 Some produce a limited aerial mycelium which is structurally similar to 

 that of the vegetative mycelium. Some of the species are acid-fast. 



1. Nocardia farcinica Trevisan. (Nocard, M. E., Ann. Inst. Pasteur, 

 2, 1888, 293; Trevisan, V., / generi e le specie delle Batteriacee, Milan, 

 1889, 9). 



Mycelium: Filaments 0.25 /x thick, branched. Markedly acid-fast. 



Nutrient agar: Colonies yellowish white, irregular, refractive, fila- 

 mentous. 



Potato: Growth abundant, dull, crumpled, whitish yellow. 



Gelatin: Small, circular, transparent, glistening colonies, No liquefaction. 

 No proteolysis. 



Milk: Unchanged. 



Starch: No hydrolysis. 



Nutrient broth: Clear, with granular sediment, often with gray pellicle. 



Nitrates: No reduction. 



Temperature: Optimum 37°C. 



Source: Cases of bovine farcy. 



Remarks: No soluble pigment formed. 



2. Nocardia asteroides (Eppinger) Blanchard. (Eppinger, H. L., Beitr. 

 Pathol. Anat., 9, 1891, 287; Blanchard, in Bouchard, Traite" Pathol. Gen., 

 2, 1895, 811). 



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