NON-SPECIFIC PYOGENIC COCCI 



203 



virulent strains. Bacteriolysins are probably not important. 

 Opsonins, normal and immune, and the phagocytosis induced by 

 them, probably explain any immunity which is exhibited by the 

 body. This immunity, like others produced by opsonins, is not 

 lasting; in fact, it is so transient that it may be said that an attack 

 of erysipelas, for example, renders one even more subject to recur- 

 rence. 



Treatment by the use of bacterins, and particularly autogenic 

 vaccines, has been found successful in chronic suppurations in 

 both man and animals. In acute attacks it is of little or no value. 

 It seems to be the consensus of opinion among investigators that 

 the use of a polyvalent 

 vaccine is more efficaci- 

 ous than a univalent 

 when it is not autogenic. 



Antistreptococcic sera 

 are produced for. use by 

 both the veterinarian 

 and the physician. The 

 serum of Marmorek is 

 prepared by the use of 

 a culture having such 

 virulence for rabbits 

 that j^ooo c -c- proves 

 fatal. Horses are im- 



Fig. 



87. Streptococcus pyogenes 

 (Frankel and Pfeiffer). 



in pus 



munized by repeated in- 

 jections of such broth 



cultures and their serum used. This seems to be of distinct 

 benefit in immunizing passively an animal against the same 

 strain, but does not protect against others. Polyvalent sera 

 are prepared by immunizing horses against a considerable number 

 of strains of the Streptococcus. The results from the use of 

 such sera have not proved as successful as hoped, though some 

 have reported excellent results. Such a serum doubtless owes 

 its protective influence to its opsonic content, but Hektoen and 

 Ruediger have shown that in some antistreptococcic sera on the 

 market the opsonin content was below normal. The advisability 

 of the use of antistreptococcic serum in general streptococcic 



