618 



ORDER IV. EUBACTERIALES 



Rods, usually slightly thinner, in long 

 chains twisted together to form strands. 



Agar colonies: Grayish, thin, widely 

 spreading by means of long, twisted chains 

 of cells, turning to the left or right (sinistral 

 or dextral). The sinistral form occurs more 

 often in soil (Gause, Mikrobiologia, 18, 

 1949, 154). 



Agar slants: Growth thin, rhizoid, gray- 

 ish, widely spreading, adhering to or grow- 

 ing into the agar. With aging, growth be- 

 comes thicker and softer. 



Gordon (Jour. Bact., 39, 1940, 98) and 

 Smith, Gordon and Clark (op. cit., 1952) 

 showed that Bacillus mycoides lost its rhi- 

 zoid character if grown from a small inocu- 

 lum in flasks containing 100 ml of broth and 

 plated on agar after 3 to 30 days. The result- 

 ing non-rhizoid cultures could not be differ- 

 entiated from Bacillus cereus. Dissociation 

 occurred under other conditions, but not so 

 rapidly or completely. Reversion to the 

 rhizoid state was not observed, although 

 the dissociants were grown under a variety 

 of conditions intended to induce such re- 

 version. 



Source: Isolated from soil. 



Habitat: Widely distributed in soil. 



3. Bacillus anthracis Cohn, 1872, 

 emend. Koch, 1876. (Les infusories de la 

 maladie charbonneuse, Davaine, Compt. 

 rend. Acad. Sci., Paris, 69, 1864, 393; Cohn, 

 Beitrage z. Biol. d. Pflanzen, ^, Heft 2, 1872, 

 177; Koch, ibid., 2, Heft 2, 1876, 279; Bac- 

 teridie des charbon, Pasteur and Joubert, 

 Compt. rend. Acad. Sci., Paris, 84, 1877, 

 900.) 



an'thra.cis. Gr. noun anthrax charcoal, a 

 red precious stone, a carbuncle; M.L. noun 

 anthrax the disease anthrax; M.L. gen.noun 

 anthracis of anthrax. 



Rods, 1.0 to 1.3 by 3.0 to 10.0 microns, 

 with square or concave ends, occurring in 

 long chains; resemble Bacillus cereus. When 

 lightly stained, protoplasm granular or 

 foamy. Encapsulated. Non-motile. Gram- 

 positive. 



Spores ellipsoidal to cylindrical, 0.8 to 1.0 

 by 1.3 to 1.5 microns, central or para- 

 central, often in chains. Germination polar. 



Sporangia ellipsoidal to cylindrical, not 

 definitely swollen, in chains. 



Gelatin stab: Arborescent in depth, in- 

 verted pine tree. Liquefaction crateriform 

 becoming stratiform. 



Gelatin agar streak plate: Wide zone of 

 hydrolysis. 



Agar colonies: Large, dense, irregular, 

 composed of parallel chains of cells giving 

 a curled or combed appearance; similar to 

 certain strains of Bacillus cereus. 



Agar slants : Growth abundant, spreading, 

 dense, grayish, with irregular borders. 



Blood hemolysis : Variable (Bekker, Zent. 

 f. Bakt., I Abt., Orig., I47, 1941, 451; also 

 see ibid., 150, 1943, 326). 



Broth: Little or no turbidity; thick pel- 

 licle. 



Milk: Coagulated, slightly acid, pep- 

 tonized. 



Milk agar streak plate: Wide zone of hy- 

 drolysis of the casein. 



Potato: Growth abundant, spreading, 

 white to creamy. 



Acid but no gas (with ammonium salts 

 as source of nitrogen) from glucose, fruc- 

 tose, sucrose, maltose, trehalose and dex- 

 trin. Late and slight acidity from glycerol 

 and salicin by some strains. No acid from 

 arabinose, rhamnose, mannose, galactose, 

 lactose, rafEnose, inulin, mannitol, dulcitol, 

 sorbitol, inositol or adonitol. 

 Starch hydrolyzed. 

 Acetylmethylcarbinol produced. 

 Nitrites produced from nitrates. 

 Amino acids are necessary for growth. 

 Lecithinase produced. 

 Aerobic, facultatively anaerobic. 

 Temperature relations: Optimum, about 

 35° C. Maximum, about 43° C. 



Pathogenicity: Cause of anthrax in man, 

 cattle, swine, sheep, rabbits, guinea pigs, 

 mice, etc. (Smith, Gordon and Clark {op. 

 cit., 1952) considered Bacillus anthracis as a 

 pathogenic variety of Bacillus cereus be- 

 cause certain strains of the two were in close 

 agreement in all characters except patho- 

 genicity. As strains of Bacillus anthracis 

 may become avirulent, and as certain strains 

 of Bacillus cereus may be lethal in massive 

 dosages (Clark, Jour. Bact., 33, 1937, 435), 

 the relationship is closer than most investi- 

 gators realize.) 



