action on lactose, sucrose, mannitol or sali- cin. Nitrates rapidly reduced; nitrites absent (Reed, Jour. Bact., 4-^, 1942, 425). Coagulated albumin: No liquefaction. Blood serum: No liquefaction. Brain medium: No blackening or diges- tion. Anaerobic, although less strict than Types B and C. Optimum temperature, between 35° and 38° C. Produces an exotoxin which is toxic on injection but not on feeding. Four antigenic components have been recognized in toxic filtrates (Oakley, Warrack and Clarke, Jour. Gen. Microbiol., 1, 1947, 91; also see van Heyningen, Bacterial Toxins, C. C Thomas, Springfield, 1950, 42). These in- clude: alpha, classical lethal toxin; gamma, hemolytic lecithinase; delta, oxygen-labile hemolysin; and epsilon, probably pearly- layer-agent in egg-agar. Production of gamma toxin differentiates Type A from Types B and C. Produces a species-specific hemolysin for human red blood cells which is neutralized by selected antisera; differentiated from Clostridium septicum on this character. Pathogenic for guinea pigs, rabbits, mice, rats and pigeons. Comment: Some authors regard Clostri- dium hemolyticum Hauduroy et al., which produces a hemolytic lecithinase, as be- longing to this species. Source: Isolated from a guinea pig inocu- lated with peptonized casein; later from a human case of gaseous gangrene. Also iso- lated from human necrotic hepatitis (Mol- laret, Prevot and Gueniot, Ann. Inst. Past., 75, 1948, 195). Habitat: Probably widely distributed in manured soil. 21a. Clostridium novyi Type B, Scott et al., 1934. (Bacillus gigas Zeissler and Rass- feld. Arch. Wiss. u. Prakt. Tierheilk., 59, 1929, 419; Scott, Turner and Vawter, Proc. 12th Internat. Vet. Cong., N. Y., 2, 1934, 175.) Large rods, 1.2 to 2.0 by 10.0 to 14.0 mi- crons, occurring singh', in pairs or in chains of 3 to 4 elements. Spores ovoid, most fre- quently subterminal, onlj^ slightly swelling the cells. Motile by means of peritrichous flagella. Gram-positive. Gelatin: Good growth. No liquefaction. Glucose-gelatin: Good growth. Liquefac- tion after two weeks of incubation. Glucose blood agar surface colonies: Del- icate, thin, fiat plaques of fine filaments, dull surface, scarcely raised above surface of medium. Hemolysis variable. Egg yolk surface colonies: Small, irregu- lar, transparent, producing a wide (8 mm in diameter), regular, sharply defined circle of precipitation, without luster, under and beyond the colony. Agar deep colonies: Lenticular or bicon- vex disc, sometimes with outgrowths or filamentous, woolly colonies with opaque center or bursting-grenade colony type. Glucose broth: Abundant growth with gas; flocculent sediment. Meat infusion broth: Growth less abun- dant than in glucose broth; little or no gas; sediment. Cooked meat medium: Good growth; gas; meat not blackened. Milk: Reports variable; little action long dela3^ed, possibly late coagulation without digestion. Glucose, galactose and fructose are fer- mented. Action on glycerol and maltose variable. No action on lactose, sucrose, rhamnose, dulcitol, mannitol, inulin or sali- cin. Coagulated egg albumin: No digestion. Brain medium: No blackening unless iron- nail added. Strictlj- anaerobic. Optimum temperature, apparently 37° C; growth occurs between 24° and 43° C. An exotoxin is produced which is toxic on injection but not on feeding. Three antigenic components have been recognized in toxic filtrates (Oakley, Warrack and Clarke, Jour. Gen. Microbiol., 1, 1947, 91). These include: alpha, classical lethal toxin; beta, hemolytic lecithinase; and zeta, oxj^gen-stable hemoly- sin. Production of beta to.xin differentiates Type B from Types A and C. Pathogenic for sheep, cows, horses, pigs, fowls, rabbits, guinea pigs, rats and mice. Source: Isolated from black disease (in- fectious necrotic hepatitis) of sheep in Aus- tralia. Also isolated from similar diseases
