238 



ANTITOXINS 



Collecting and Testing the Serum. After three or four months a 

 trial bleeding should be made and the serum tested as follows : the mini- 

 mal lethal dose of a culture is determined and ten times this amount 

 placed in a series of tubes or syringes with increasing doses of serum; 

 the total quantity of injection is made up to 4 c.c. with sterile salt solu- 

 tion. The mixtures are set aside for one hour at 35 C. and injected in- 

 travenously in young rabbits. The animals are to be observed for at 

 least five days for diarrhea, paralysis and loss in weight. 



TABLE 4. METHOD OF TESTING ANTIDYSENTERIC SERUM (KRUSE- 



SHIGA) 



In this instance 0.004 c.c. of serum was sufficient to protect young 

 rabbits against 10 fatal doses of culture, and demonstrated that it is 

 possible to secure a fairly potent serum against the toxins of the Kruse- 

 Shiga microorganism. 



According to Todd, if the antiserum is given at least one-half hour 

 after administering the culture, it will protect the rabbit. If given 

 twenty-four hours later, it affords no protection. Similarly, the mix- 

 tures of culture and serum must not be injected immediately after mix- 

 ing, as the results are more irregular than if they are allowed to stand for 

 one-half to one hour before injecting. 



If the trial bleeding shows a satisfactory serum, the horse is bled 

 aseptically, as was previously described, and the serum is separated and 

 preserved with 0.5 per cent, phenol in quantities of 10 c.c. in sterile 

 containers. As there is no official immunity unit, the serum is admin- 

 istered in doses of from 5 to 10 c.c. until a therapeutic effect is secured. 



ANTISTAPHYLOCOCCUS SERUM 



Both Staphylococcus pyogenes aureus and S. pyogenes albus have 

 been shown to produce certain soluble toxins, such as a leukocidin and 

 a hemolysin, which are partly responsible for the tissue destruction and 

 symptoms that accompany these infections. Severe Staphylococcus 



