STREPTOCOLYSIN 603 



2. Marmorek sowed a passage organism of increased virulence on human - 

 serum-broth and after incubating for 3 months filtered it through porcelain. 



The filtrate inoculated in doses of 1 c.c. into a rabbit weighing 2 kg. killed the 

 animal in 3 or 4 days. The virulence of the toxin was diminished by heating at 

 58 C. 



Marmorek prepared another, more powerful, toxin by growing the organism 

 in broth to which a little leucin and glycocoll and some guinea-pig leucocytes 

 had been added. 



3. Bonome and Bombicci are of opinion that the toxin of the streptococcus 

 is an endotoxin. 1 By treating streptococci with 10 volumes of a 0'75 per cent, 

 solution of potash, filtering and precipitating with a 1 per cent, aqueous 

 solution of acetic acid, they obtained a product which was toxic for rabbits. 

 Rabbits inoculated with gradually increasing doses of the filtrate acquired a 

 slight degree of immunity against the organism used in the preparation of 

 the toxin but not against any other strain. 



Hsemolysin. (Streptocolysin.) 



Marmorek observed that the streptococcus is capable of producing an 

 haemolysin in the tissues of living animals and in this way appeared to differ 

 from all other organisms. He considered that all streptococci of human 

 origin were haemolytic, and adduced this opinion in further support of his 

 reasons for regarding all such streptococci as identical. 



[Schlesinger however has described streptococci, both pathogenic and non- 

 pathogenic, which were not haemolytic.] Besredka also has isolated strains 

 of streptococci which not only did not produce haemolysis in vitro but, and 

 this is very uncommon, were non-haemolytic in vivo. [Schottmiiller observed 

 the same fact and, as has already been pointed out, divides streptococci into 

 three groups according to the extent of haemolysis produced when grown on 

 blood-agar (p. 599). Andrewes and Horder find that among the pathogenic 

 streptococci examined by them those referable to their " pyogenes " and 

 " anginosus " groups alone produce haemolysis on blood-agar,] 



Besredka has investigated the nature of the streptococcal haemolysin. 



Cultures in Marmorek's ascitic broth are powerfully haemolytic but lose 

 this property on being filtered through a Chamberland bougie. [Besredka, 

 however, points out that the phenomenon of haemolysis in unfiltered cultures 

 is of only minor importance ; most micro-organisms are more or less haemolytic 

 in artificial culture but, curiously enough, lose this property on filtration. In 

 the case of a few streptococci, however, a specific haemolysin ( Streptocolysin) 

 is formed which is filtrable, and for the test of haemolysis to be of value filtered 

 cultures should be used.] 



Preparation of Streptocolysin. Besredka recommends the following technique for 

 the preparation of a powerful Streptocolysin : 



Inject a few drops of a 24-hour culture of a streptococcus in ascitic-broth beneath 

 the skin of a rabbit. Next day, as soon as the animal is dead, ascertain that the 

 red cells are dissolved, and then sow two or three drops of the heart's blood into 

 a tube of pure rabbit-serum or equal parts of broth and horse-serum. Incubate 

 for 24 hours, then add an equal volume of normal saline solution and filter through 

 a Chamberland bougie. 



The filtrate readily dissolves rabbit, human, guinea-pig and sheep red-cells 

 and to a less extent those of the horse and bovine animal : it is most actively 

 haemolytic at 37 C. It is not toxic. Attempts to immunize animals with 

 the object of preparing an anti-haemolysin have failed. 



At the temperature of the laboratory, Streptocolysin deteriorates in a few 



1 Simon considers that there is both an endotoxin and an extra-cellular toxin. 



