FAMILY ACTINOMYCETACEAE 



907 



the densest part of the growth on s\ni- 

 thetic glj^cerol agar. Angular branching 

 with division of the substratum filaments 

 can be seen, the aerial hyphae also being 

 irregularly segmented. Acid-fast. 



Gelatin : Poor gi'owth, a few irregular 

 colorless flakes. Xo liquefaction. 



Agar: No growth. 



Glucose agar: Raised, granular, pink 

 colonies with white aerial mycelium. 



Glycerol agar : Small pink coiled masses 

 with thin white aerial mycelium. 



Potato agar: No growth. 



Coon's agar: Colorless growth with 

 liberal white aerial mycelium. 



Dorset's egg medium : Small irregularly 

 raised and coiled dull pink mass. 



Serum agar: Very poor growth. 



Inspissated serum : Scant colorless 

 flaky growth; later a minute tuft of pale 

 pink aerial mycelium. 



Broth: Moderate flaky growth. 



Synthetic sucrose solution : Poor 

 growth, a few flakes on surface, a few 

 at bottom. 



Potato plug: Dry, raised, convoluted, 

 pink growth with white aerial mycelium 

 in one month; dull, pink, brittle surface 

 colonies, with paler aerial mycelium 

 floating coherently on liquid at base in 2 

 months . 



Milk: No change. 



Starch not hydrolyzed. 



Source : From a case of mycetoma of the 

 foot in South Africa. 



Habitat : Human infections so far as 

 known. 



19. Nocardia mesenterica (Orla-Jen- 

 sen) comb. nov. (Microbacterium mesen- 

 tericum Orla-Jensen, The Lactic Acid 

 Bacteria, 1919, 181 j Proactinomyces mes- 

 entericus Jensen, Proc. Linnean Soc. 

 New So. Wales, 57, 1932, 373.) From 

 Greek mesenterium, mesenter3^ 



Extensive mj-celium composed of 

 richly branching hyphae of a somewhat 

 variable thickness, 0.4 to O.S micron; no 

 aerial hyphae are seen. With increasing 

 age the hyphae divide into fragments of 



varying size and shape, partly diphthe- 

 roid rods, but no real cocci. There is, 

 particularly in richer media, a tendency 

 to form large, swollen, fusiform to almost 

 spherical cells, up to 3.5 microns in 

 diameter. These may stain intensely 

 with carbol fuchsin ; when transferred to 

 fresh media, the}' germinate and produce 

 a new mycelium. 



Gelatin: Good growth; finely arbores- 

 cent, cream-colored growth in the stab; 

 raised, folded, pale-yellow, surface 

 colony. No liquefaction. 



Glucose-asparagine-agar : Fair growth, 

 narrow, raised, granular, very pale yel- 

 low, glistening; condensation water clear, 

 with small granules. At 30°C only scant 

 growth consisting of small irregular white 

 granules, growing deeply down into the 

 agar. 



Glucose-nutrient-agar : Good growth, 

 restricted, with undulate edges, surface 

 with high transverse folds, cream- 

 colored; the consistency is firm and car- 

 tilaginous after 2 daj's, later looser and 

 more brittle. Growth at 28° to 30°C 

 rather scant; smooth, soft, glistening, 

 cream-colored smear, 



Sabouraud's agar: E.xcellent growth, 

 spreading, at first flat and smooth, pale 

 straw-yellow, perfectly hard and car- 

 tilaginous, later raised and strongly 

 folded, of a loose, curd-like consistency, 

 bright lemon-yellow. Growth at 28° to 

 SO^C onlj' fair, restricted, folded, cream- 

 colored, soon becoming soft and smeary. 



Potato: Scant growth; restricted, soft, 

 cream-colored smear. 



Broth: Good growth; voluminous, 

 flaky, whitish sediment ; broth clear. 



Milk: At 28° to 30°C, small cream- 

 colored granules along the tube ; the milk 

 undergoes no visible changes within 4 

 weeks. No proteolytic action. 



Indole not formed. 



Sucrose is inverted. 



Starch is hydrolyzed. 



Cellulose is not decomposed. 



Nitrates are reduced to nitrites. 



No growth in o.xygen-free atmosphere. 



