CLOSTRIDIUM BOTULINUM 



879 



broth culture injected intramuscularly into a guinea-pig causes digestion of skin 

 and muscles, and a hsemorrhagic liquefaction of the softer parts of the limb. This 

 digestion may spread over the abdomen, and death occur during the next 12 to 

 24 hours ; or recovery may follow with more or less complete necrosis of the limb. 

 The fluid contains no gas and is not putrid. 

 (See Weinberg and Seguin 1918, Report 1919, Hall 1922, Torrcy 1925, Weinberg et 

 al. 1926.) 



Clostridium botviliuum 



Isolation. — By van Ermengem from ham in 1896 (1896, 1897). Several other organism- 

 have since been isolated from botuUsm-like diseases in animals. These are some, 

 times referred to as CI. parabotulinum, but it is probably better to give them letters 

 using A and B to refer to the two main toxigenic types. Type C^^ was isolated by 

 Bengtson (1922a, b, 1923) and by Graham and Boughton (1923a, b) in the United 

 States from chickens and ducks ; Type C^ by Seddon ( 1922) in Australia from 

 cattle ; Type D by Theiler and his colleagues ( 1926) in South Africa from cattle, 

 and Type E by Theiler (1928) in South Africa from horses. The relation between 

 Types C, D and E is not yet entirely clear, but Types C and E are said to be 

 identical. Following description refers chiefly to Types A and B. 

 Habitat. — Widely distributed in soil, both virgin and cultivated. Not infrequently present 



in intestinal tract of domestic animals. 

 Morphology. — i-day agar slope at 37° C. Rather large, stout rods, 4-6 fi X 0-9 /ii ; axis 

 straight, parallel sides, and slightly rounded ends ; arranged singly, or sometimes 

 in pairs or chains. Variations in depth of staining. Spores are oval, wider than 

 the bacillus, thick- walled, and situated at or near the end. Free spores are numer- 

 ous. Some strains spore readily, others hardly at all. Spores formed best in 

 sugar-free media. Sluggishly motile by 4-8 peritrichate flagella. No capsule. 

 Gram-positive in young cultures. 



Agar Plate. — 4 days at 31° C. Irregu- 

 larly round, 5-10 mm. in diam- 

 "— eter, glistening, translucent, effuse, 



^ filamentous colonies, with an 



\» alternately smooth and granular 



•^^ < ^'^'^ surface (due to crossing of fila- 



^; 



^*^' 



Fig. 197. — Clostridium botulinum. 



From a surface agar culture anaerobicallv, 

 2 days, 37° C. (X 1000). 



Fig. 



1 98. — Clostridium 

 linum. 



botu- 



Surface colonv on agar, anaerobi- 

 cally, 2 days, 37° C. ( X 8). 



ments), and an indefinite, fimbriate, reticular edge. Greyish-yellow by reflected, 

 bluish-grey by transmitted light. Butyrous consistency, easily emulsifiable. 

 Differentiated into thicker, browner centre, and thinner, more tran.slucent peri- 



