CHAPTER XXXI 

 BACILLUS TETANI 



Lockjaw or tetanus, though a comparatively infrequent disease, 

 has been recognized as a distinct clinical entity for many centuries. 

 The infectious nature of the disease, however, was not demonstrated 

 until 1884, when Carlo ^ and Rattone succeeded in producing tetanus in 

 rabbits by the inoculation of pus from the cutaneous lesion of a human 

 case. Nicolaier,^ not long after, succeeded in producing tetanic symp- 

 toms in mice and rabbits by inoculating them with soil. In connec- 

 tion with the lesions produced at the point of inoculation, Nicolaier 

 described a bacillus which may have been Bacillus tetani, but which he 

 was unable to cultivate in pure culture. Kitasato,' in 1889, definitely 

 solved the etiological problem by obtaining from cases of tetanus pure 

 cultures of bacilli with which he was able again to produce the disease 

 in animals. 



Kitasato succeeded where others had failed because of his use of 

 anaerobic methods and his elimination of non-spore-bearing con- 

 taminating organisms by means of heat. His method of isolation 

 was as follows: The material containing tetanus bacilli was smeared 

 upon the surface of agar slants. These were permitted to develop at 

 incubator temperature for twenty-four to forty-eight hours. At the end 

 of this time the cultures were subjected to a temperature of 80° C. for 

 one hour. The purpose of this was to destroy all non-sporulating 

 bacteria, as well as aerobic spore-bearers which had developed into 

 the vegetative form. Agar plates were then inoculated from the slants 

 and exposed to an atmosphere from which oxygen had been com- 

 pletely eliminated and hydrogen substituted. On these plates colonies 

 of tetanus bacilli developed. 



Morphology and Staining. — The bacillus of tetanus is a slender bacil- 

 lus, 2 to 5 micra in length, and 0.3 to 0.8 in breadth. The vegetative 

 forms which occur chiefly in young cultures are slightly motile and are 



' Carlo e Rattone, Giomale d. R. Acad. d. Torino, 1884. 

 ' Nicolaier, Inaug. Diss., Gottingen, 1885. 

 5 Kitasato, Deut. med. Woch., No. xxxi, 1889. 

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