ANTISTAPHYLOCOCCUS SERUM 249 



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 

 infection is probably due in part to the paralyzing effect and actual de- 

 structive action of the leukocidin upon the leukocytes, preventing, for 

 the time being, the walling-off of the lesion and effectual phagocytosis. 

 Antistaphylococcus serums have been shown to counteract the action 

 of the leukocidin and the hemolysin, and may be useful in the treatment 

 of severe, spreading, or metastatic staphylococcus infections. 



According to Neisser and Wechsberg, during staphylococcus dis- 

 ease an antihemotoxin is produced against the hemotoxin of the cocci; 

 later Bruck, Michaelis, and Schulze attempted to show that a demon- 

 stration of this antistaphylolysin in the serum may be regarded as evi- 

 dence of a staphylococcus infection. 



Preparation of Antistaphylococcus Serum. For immunization pur- 

 poses several different cultures of the Staphylococcus aureus should be 

 used, in order that the antiserums may be polyvalent. Goats or horses 

 may be employed. Cultures may be grown on neutral agar for forty- 

 eight hours, and an emulsion, equivalent to half an agar slant, heated to 

 60 C. for one hour and injected subcutaneously in an adult goat. If 

 10 different strains are used, a four-millimeter loopful from each culture, 

 emulsified in 5 c.c. of sterile salt solution, will be about the proper dose 

 for the first injection. ^ Subsequent doses are given at intervals of a 

 week, and are rapidly increased in size until full, living, unheated cul- 

 tures are injected intravenously without harm to the animal. The 

 serum may be tested by determining its content of antilysin or of bac- 

 teriotropin. Complement-fixation tests are occasionally useful for 

 obtaining an insight into the quantity of bacteriolysin present. 



Technic of the Antilysin Test. The object of this test is to determine 



