CHAPTER XXXII. 



tetanus, rabies, and louping-ill. 



Tetanus. 



Tetanus is a communicable disease of man and the lowei- animals, 

 characterised by spasmodic contraction of the muscles. It is com- 

 monly the result of an injury, and occurs especially after wounds 

 produced by means of sphnters of wood or contaminated with earth 

 or dust, and may follow after surgical operations. 



Carle and Rattone first showed, in 1884, that the disease could 

 be communicated from man to other animals. Rabbits inoculated 

 with pus from a case in man developed tetanus, and from these 

 rabbits the disease was conveyed to others. Nicolaier, the following 

 year, found that mice and rabbits inoculated with earth often 

 contracted tetanvls, and that the pus which formed at the seat of 

 inoculation contained, amongst other organisms, characteristic bacUli. 

 Pure cultures were first obtained by Kitasato. 



Bacillus of Tetanus. — Slender, straight rods, and filamentous 

 forms. Spore formation takes place at the end of a bacillus, giving 

 it a drumstick appearance. They stain with aniline dyes, but, best 

 with Neelsen's solution, or by Gram's method. By the Ziehl-Neelsen 

 method and methylene-blue, the spores can be stained red, in 

 contrast to the bacilli, which are stained blue. The bacilh. are 

 anaerobic, liquefy gelatine, and are slightly motile. They can be 

 grown at the ordinary temperature, but most readily at the tem- 

 perature of the blood, in an atmosphere of hydrogen, especially after 

 the addition of 1 or 2 per cent, of grape sugar to the nutrient 

 medium. The young colonies on plate-cultivations somewhat 

 resemble those of Bacillus subtilis. They have an opaque centre, 

 and are surrounded by fine rays, extending in all directions like 

 thistle-down. In the depth of gelatine a ray-Hke growth occurs 

 in the lower part of the track of the needle. The gelatine is lique- 

 fied very slowly, and gas is given off. The cultures possess a 



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