:.4 



THE ACTINOMYCOTIC Vol. II 



Source : Human pulmonary case of st repl o- 

 thricosis. 



45. Nocardia rhodnii (Erikson, 1935) 

 Waksman and Henrici, 1948 (Erikson, D. 

 Med. Research Council Spec. Rept. Ser. 

 203: 29, 1935). 



Morphology: Substrate growth made up 

 of minute colonies, composed of hyphal seg- 

 ments arranged in angular apposition. Aerial 

 mycelium is short and straight. Later, 

 growth becomes extensive and spreading, 

 made up partly of long, branching filaments, 

 and partly of short segments exhibiting 

 slipping branching, each giving rise to 

 aerial hyphae. Angular branching very 

 marked, delicate, spreading, herringbone 

 patterns being formed. 



Sucrose uitrate agar: Colonies minute, 

 colorless, round. 



Glucose-asparagine agar: Growth abun- 

 dant, coral-pink, convoluted, piled up. 



Glycerol agar: Growth made up of dull 

 pink colonies, round and umbilicated, he- 

 coming piled up and deeper coral-red. 



Potato agar: Growth abundant, pink, 

 piled up and stiff. Aerial mycelium white at 

 top of slant . 



Egg medium: Membrane salmon-pink, 

 granular. 



Gelatin: Colonies pale pink, in form of 

 surface pellicle and as sediment. Liquefac- 

 tion rapid. 



Milk: Growth bright orange. Medium 

 unchanged. 



Nutrient broth: Salmon-pink flakes in 

 sediment and colonies on surface. Medium 

 discolored. 



Source: From reduviid bug, Rhodnius 

 prolixus. 



Type culture: [MRU 653. 



4(i. Nocardia rubra (Actinomyces ruber 

 sterilis Krassilnikov, 1949) Waksman (Kras- 

 silnikov, X. A. ( ruide to the identification of 

 bacteria and actinomycetes. Moskau, 1949). 



Agar media : ( rrowth red, smooth, nodular, 



slightly lustrous with a gravel-like appear- 

 ance. Xo aerial mycelium produced under 

 laboratory conditions. .Most strains form no 

 soluble pigment. Some produce a brownish 

 substance. Slightly acid-fast (Fig. 12). 



Milk: Unchanged. 



Krassilnikov examined 25 different strains 

 said to belong to this type, but differing 

 from one another in intensity of color and in 

 certain physiological properties. He believed 

 that under certain conditions of growth these 

 cultures would develop an aerial mycelium 

 and proper sporulation. 



This group was divided by Krassilnikov 

 into four subgroups: 



a. Flat, compact colonies, red to pink in 

 color, pigment insoluble. Gelatin not lique- 

 fied, milk unchanged or only peptonized; 

 starch not decomposed; nitrate not reduced. 



b. Colonies raised, dry, crumbling at con- 

 tact with loop; red to brownish-red in color. 

 Ready growth on synthetic media. Gelatin 

 liquefied slowly; milk coagulated slightly or 

 only peptonized; nitrate reduced to nitrite; 

 ready growth in paraffin and fats. 



c Colonies compact, growing deep into 

 substrate; pink to light red in color; brown 

 substance excreted into substrate. Gelatin 

 slightly liquefied; milk peptonized by some 

 strains, starch slightly decomposed; nitrates 

 not reduced to nitrites. Some cultures grow 

 slowly in cellulose. Do not grow on paraffin. 



d. Flat or nodular colonies, growing com- 

 pactly into medium. Frequently develop 

 coremia on the surface; these consist of 

 thickly interwoven sterile hyphae. The cul- 

 tures grow poorly on artificial media. Gelatin 

 not liquefied or only slowly; milk not 

 changed or only slightly peptonized; starch 

 not decomposed. No growth on cellulose. 

 Ready growth on fats, paraffin, and wax. 



Remarks: Krassilnikov considers this 

 group to comprise transition forms between 

 Streptomyces and Nocardia. N. corallina is 

 believed to be a related form; a number of 

 synonyms are listed such as N. agrestis, N. 



