878 CLOSTRIDIUM 



Deep Glucose Agar Shake.— 4 days at 37° C. No gas. Abundant growth through 

 out medium. Colonies are 1 mm. in diameter, irregularly round, opaque, brown 

 with blunt, coral-like projections with very fine woolly ends. 



Horse Blood Agar Plate. — 4 days at 37° G. Irregularly round colonies, slightly raised, 

 2-3 mm. in diameter, with irregularl}' lobate edge, and smooth or pitted surface. 

 No haemolysis. 



Agar Slope.- — 4 days at 37° C. Moderate, partly confluent, effuse, glistening, translucent, 

 greyish-yeUow growth with beaten-copper surface and delicate fimbriate edge. 



Oelatin. — Liquefied in 3 days at 37° C. 



Broth. — 4 days at 37° C. Moderate growth, with moderate turbichty, and a granulo- 

 powdery deposit partly disintegrating ; slight fcBtid odour. 



Loeffler's Serum. — 15 days at 31° C. Almost completely digested ; the fluid is almost clear. 



Coagulated Egg. — 15 days at 37° C. Partly digested ; butt turned bluish-green. 



Cooked Meat Medium.— 15 days at 37° C. Abundant growth ; meat digested and slightly 

 blackened ; long column of sHghtly turbid fluid ; gas produced ; a deposit of 

 white tyrosine crystals occurs, increasing with age. Slightly foetid odour. 



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Fro. 196. — Clostridium histolyti- 

 FiG. 195. — Clostridium histolyticum. cum. 



From a surface culture on agar anaerobically, Surface colony on agar anaerobi- 



6 days, 37° C. ( X 1000). cally, 2 days, 37° C. ( x 8). 



Resistance. — Killed in 6 minutes at 105° C. (moist heat). 



Metabolism. — Microaerophilic. Opt. temp. 37° C. No haemolysis on horse blood agar 

 plates. Hsemolyses human but not sheep's red cells. Nutritional : grows well 

 in ordinary media ; growth not improved by glucose. Green fluorescent colonies 

 on MacConkey plate. Forms a fibrinolysin. 



Biochemical. — Some strains produce acid, but no gas, in glucose, and occasionally in maltose. 

 No fermentation of mannitol, lactose, sucrose or salicin ; sometimes no acid pro- 

 duced at all. Indole — ; M.R. — : V.P. — ; nitrates not reduced ; NH3 — ; 

 HoS -f -i- -f ; M.B. reduction — ; catalase -f- weak. Litmus milk : casein pre- 

 cipitated and digested ; reduction ; after 8 to 10 days it is transformed into a 

 clear, amber-coloured fluid. 



Antigenic Structure. — Agglutinating sera seem to act chiefly on homologous strains. Anti- 

 toxin can be prepared by injection of toxin into horses. 



Pathogenicity. — Exotoxin is said to be formed in very young cultures. Natural patho- 

 genicity doubtful ; appears often in gangrenous processes in man. Experimentally, 

 strains vary in pathogenicity ; susceptible animals are guinea-pig, rabbit, and 

 mouse. Bacillus is actively proteolytio and digests living tissue. 1 ml. of a young 



