888 CLOSTRIDIUM 



variation in pathogenicity of different strains. Washed bacilli or spores are non- 

 pathogenic. 0- 1-1-0 ml. broth culture injected intramuscularly into guinea-pig 

 causes local tumefaction, spreading oedema, and death in 24 to 48 hours. P.M. 

 suprarenal glands congested. Also pathogenic to mice, pigeons, and less so to 

 rabbits (see p. 870). B type is responsible for lamb dysentery, C type for 

 " struck " — an enteritis of sheep — and D type for an enterotoxsemic disease and 

 for pulpy kidney disease of sheep (see Chapter 78). 

 (See Kamen 1904,Simonds 1915ra, h, c, Robertson 1916, Bull 1917, Bull and Pritchett 

 1917a, h, De Kruif and Bollman 1917, De Kruif et al. 1917, Weinberg and Seguin 1918, 

 Report 1919, Bengtson 1920, 'Jaulfeild 1920, Hall 1922, Humphreys 1924, DaUing 1926, 

 Weinberg and Ginsbourg 1927, Howard 1928, Weinberg 1929, Weinberg and Combiesco 

 1930, McEwen 1930, Torrey, Kahn and Salinger 1930, Headlee 1931, Mason, Ross and 

 DaUing 1931, Wilsdon 1931, 1933, Bennetts 1932, Glenny et al. 1933, Walbum and 

 Reymann 1933, McGaughey 1933, Livesay 1933, Weinberg and Guillaumie 1936.) 



Clostridium tetani 



Isolation. — Described by Nicolaier in 1884; isolated by Kitasato in 1889 (18896). 



Habitat. — Found in soil — especially cultivated soil — and in the intestine of man and 

 animals. 



Morphology. — 4:-day agar slope at 37° C. Rods, 2-5 /< X 0-5 fi ; considerable varia- 

 tion in length ; long, curved, filamentous forms are not uncommon. Axis 

 straight, sides parallel, ends rounded ; arranged singly and occasionally in 

 chains. Variation in depth of staining. Spores spherical, terminal, and wider 

 than the bacillus, giving characteristic drum-stick appearance. Sluggishly 

 motile ; peritrichate flagella. No capsule. Strongly Gram-positive in young 

 cultures. In early stages, spores stain solidly ; later, only the thin wall stains ; 

 spores rarely become free. Bizarre involution forms appear in old cultures. 







\\ -^ 



\ 



\ 



■I 



Fig. 208. — Clostridium tetani. Fig. 209. — Clostridium tetani. 



From a surface agar culture anaerobically, From a broth culture anaerobically, 7 days, 



7 days, 37° C, showing ring form of stain- 37° C, showing the spores stained solidly 



ing ( X 1000). ( X 1000). 



Agar Plate. — 4 days at 37° G. Irregularly round, 2-5 mm. in diameter, effuse, ghstening, 

 translucent, greyish-yellow colonies with irregularly granular surface, and ill- 

 defined edge, showing filamentous, curled projections; structure very finely 

 granular or filamentous ; butyrous consistency, emulsifying easily. Some 

 strains form colonies differentiated into thicker, translucent, yellowish-brown 

 centre, and thinner, transparent, almost colourless periphery. Whole colony has 



