452 



ORDER IV. EUBACTERIALES 



cultures the filaments are homogeneous 

 and composed of single cells; with increas- 

 ing age, fine granules and alternate light 

 and dark bands appear in the filaments 

 together with a tendency to fragment into 

 irregular, bacillary and coccobacillary ele- 

 ments which give the typical strepto- 

 bacillary appearance. Under certain con- 

 ditions, large, spindle-shaped or spherical 

 swellings, sometimes packed with gran- 

 ules, are very common, occurring any- 

 where, terminally, subterminally or 

 centrally, in the rods and filaments. 

 Besides these cellular swellings, extra- 

 cellular, ether -soluble, oil -droplet -like 

 globules are very characteristic ; these have 

 been shown to consist mainly of cholesterol 

 (Partridge and Klieneberger, Jour. Path, 

 and Bact., 52, 1941, 219). The morphology, 

 to a considerable extent, depends upon the 

 medium, culture conditions and the age of 

 the culture. Under favorable conditions the 

 cells tend to be regular and rod-shaped, 

 while under unfavorable conditions pleo- 

 morphism is most pronounced. In smears 

 from pathological material, such as exudates 

 or blood from infected animals, the cells 

 occur only as rods or occasionally as short 

 filaments which lie singly or in clumps 

 without definite arrangement. True branch- 

 ing has often been reported, but it is now 

 generally recognized that branching does 

 not occur. Not encapsulated. Non-motile. 

 The Monilia-\\k.e swellings take stains more 

 intensely than do the filaments; they do not 

 take the spore stain. Not acid-fast. Gram- 

 negative; sometimes reported to be weakly 

 and irregularly Gram-positive in very 

 young cultures. 



Requires media enriched with ascitic 

 fluid, blood serum or whole blood. CO 2 

 generally does not stimulate growth. Mois- 

 ture is essential for good growth; incubation 

 of cultures on solid media in incubators 

 wath a moisture-saturated atmosphere is 

 recommended. 



Gelatin: No liquefaction. 



Plain and glucose agarorbroth: No growth 

 with recently isolated strains; occasionally 

 very slight growth after prolonged artificial 

 culture. 



Ascitic fluid or serum agar: Discrete colo- 

 nies, 1.0 to 2.5 mm in diameter after 3 days, 

 circular or irregularly round with sharp 



edges, low-convex, colorless or grayish to 

 whitish, smooth glistening surface, buty- 

 rous consistency. Smaller colonies (type X 

 colonies of Brown and Nunemaker, Bull. 

 Johns Hopkins Hosp., 70, 1942, 201; a. colo- 

 nies of 0rskov, Acta Path, et Microbiol. 

 Scand., 19, 1942, 575), which have a rough 

 and more coarsely granular appearance, 

 are sometimes found; these colonies are 

 intermediate in size and structure between 

 those of the streptobacilli and those of the 

 Li forms. 



Horse-blood agar colonies: Similar to 

 those on serum agar. No hemolysis or change 

 of color. 



Loeffler's serum colonies: Smaller than 

 those on serum agar, being less than 1 mm in 

 diameter. 



Ascitic fluid and serum broth: Whitish, 

 flocculent growth at the bottom or along 

 the side of the tube in 24 hours; growth oc- 

 curs either as small, compact balls or 

 granules with perfectly clear supernatant 

 fluid or as soft, fluffy masses, occasionally 

 with some general turbidity. No surface 

 growth. No odor. 



Medium composed of equal parts of gly- 

 cerol extract of potato and infusion broth to 

 which egg yolk is added (Parker and Hud- 

 son, op. cit., 1926, 357): Excellent growth. 



Milk : Growth generally poor ; good growth 

 is reported bj' some authors. No coagula- 

 tion. 



Indole not produced. 



Hydrogen sulfide produced in slight or 

 moderate amounts. 



Acid from glucose, fructose, maltose, 

 galactose, mannose, glycogen, dextrin and 

 starch. Sucrose, lactose and salicin may or 

 may not be attacked. No acid from xylose, 

 inulin, dulcitol, rhamnose, arabinose, 

 inositol, raffinose, sorbitol, trehalose, gly- 

 cerol or mannitol. 



Nitrites not produced from nitrates. 



Urea not hydrolyzed. 



Methylene blue is rapidly reduced. 



Sodium tellurite not reduced. 



Catalase-negative. 



Oxidase-negative. 



Aerobic, facultatively anaerobic; anaero- 

 bic conditions sometimes produce the best 

 growth on primary isolation. 



Optimum temperature, between 35° and 

 38° C. No or scant growth at 22° C. 



