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The Isolation and Serological Differentiation of Bacillus tetani. 



By W. J. TuLLOCH, M.D., Temp. Capt. E.A.M.C. (Lecturer on Bacteriology 

 at the University of St. Andrews). 



(Communicated by Sir David Bruce, F.E.S., Chairman of the W.O. Committee for 

 the Study of Tetanus. Received November 9, — Eevised December 28, 1917.) 



(From the Laboratories of the Eoyal Army Medical College and the Lister Institute 



of Preventive Medicine.) 



Synopsis. 



As the history of bacteriology has shown that conditions regarded as 

 clinical entities may be caused by a number of different organisms, it seemed 

 of importance to determine whether the Bacillus tetani is an individual 

 micro-organism, or whether there are several organisms differing from one 

 another, but all capable of elaborating a spasm-producing toxin. 



This enquiry involves the demarcation of the tetanus bacilli from similar 

 organisms and their differentiation inter se, by serological methods. 



By employing the agglutination reaction it can be shown that there are 

 at least three serological types of B. tetani. One of these, which may be 

 designated Type I, has hitherto been almost exclusively used for the pre- 

 paration of antitoxin, and, so far as is known, such antitoxin protects against 

 the toxin of all three types. 



The results obtained in the present investigation suggest that this is 

 only partially true, as the types of £. tetani isolated from cases of the disease 

 do not correspond serologically with the type in common use for the pre- 

 paration of antitoxin. This question is still under consideration, as the 

 number of cultures so far examined is too limited to permit of far-reaching 

 conclusions being drawn from the work done. 



In attempting to isolate numbers of strains of B. tetani it is found that 

 there are frequently present in the wounds of men suffering from tetanus, 

 bacilli which have morphological characters so like those of B. tetani that 

 they might readily be mistaken foi that organism. 



Serological investigation of these (non-toxic) micro-organisms, which might 

 be referred to as tetanoid bacilli, shows that they too constitute a group, the 

 members of which can be differentiated one from another by serological 

 methods. 



I. liitroduction. 



In view of the fact that bacteriological investigation has shown that con- 

 ditions which had been regarded as clinical entities were really caused by 



