PRODUCERS OP ABSCESSES, CELLULITIS AXD SEPTICAEMIA 



The above results have been repeatedly obtained, and are absolutely 

 conclusive that the serum of properly selected animals, which have 

 been repeatedly injected with living streptococci in suitable doses, 

 possesses bactericidal properties upon the same streptococcus when it 

 comes in contact with it within the bodies of animals. 



Definite protection from the serum has been obtained by many 

 reliable observers since Marrnorek's first reports. 



Is Protection Afforded by the Same Serum against all Varieties of Strep- 

 tococci? We have tested the protective value of one serum against 

 streptococci derived from five different sources. First, the streptococcus 

 Driven us by Marmorek, which was obtained from a case of angina. 

 Its virulence is now such, after having passed through hundreds Jof 

 rabbits, that 0.000001 c.c. is the average fatal dose. Second, a strepto- 

 coccus obtained from a case of erysipelas in England. Its virulence 

 is 0.00001 c.c. on the average. Third, a streptococcus obtained from 

 a case of cellulitis, its virulence being about 6 c.c. Fourth, a strepto- 

 coccus sent. me by Theobald Smith. Its virulence is such that 0.1 c.c. 

 is the average fatal dose. Fifth, another culture sent me by Smith,. 

 which grew in short chains and was obtained from milk; its virulence 

 was similar to No. 4. 



Against the first three streptococci derived from three different 

 varieties of infection existing in three different countries the serum 

 produced by the streptococcus from England had nearly the same 

 value. Against the latter two streptococci, as well as against a strepto- 

 coccus from a case of endocarditis, which resembled in some respects 

 the pneumococci arid a pneumococcus, the serum had no effect. 



The results of numerous investigators indicate that the majority of 

 streptococci met with in septic infections will be influenced by the same 

 serum. Many more streptococci, however, must be obtained from 

 human infections and tested before we can be certain of this. Those 

 obtained from cases of pneumonia and endocarditis which have some 

 resemblance to pneumococci and which are not very virulent in animals,. 

 are especially in need of investigation. 



Preparation of the Serum. Antistreptococcus serum is obtained from 

 the horse after treatment by repeated injections of living streptococcus 

 cultures of streptococci derived from human sources. As a rule, a 

 number of varieties are given at the same time so that the serum will 

 be active against any variety causing the infection. If the serum is ta 

 be used in scarlet fever, the streptococci used should be from cases of 

 scarlet fever. The procuring of a serum of the highest potency requires 

 a considerable number of animals, for some produce with the same 

 treatment a more protective serum than others. The serum must be 

 sterile from streptococcus as well as from other contaminations. 



Stability of the Serum. Unfortunately, after several weeks or months, 

 the serum, as a rule, loses most of its protective value. It should be 

 kept in a cold and dark place. 



Standardization of the Value of the Serum. The value of the serum is 

 measured by the amount required to protect against a multiple of a fatal 



