Abstract
Many cultures of staphylococci and colon bacilli recently isolated from lesions are hemolytic when grown on blood containing media and usually such organisms are proteolytic when grown in nutrient gelatin. It has not been determined whether the hemolysin is identical with or produced parallel to the proteolytic substance. Both qualities are frequently transient and may exhibit a parallel decline. An attempt was made to study these substances with reference to individuality, interdependence or homologous nature.
Filtrates of broth cultures were tested for hemolytic activity as follows: measured quantities of filtrate were added to tubes containing 1 cc. each of a 0.5% suspension of washed red blood cells, incubated at 37°C., for 1 hour, placed in the refrigerator over night and the amount of lysis observed. Proteolytic activity was determined by streaking filtrate upon the surface of an agar-gelatin medium, incubating at 37°C., for 48 hours and testing for lytic action by flooding the plate with an acid bi-chloride of mercury solution according to the method of Frazier 1 and noting any change in the character of the gelatin as indicated by a clear zone at the site of “planting”.
Filtrates of 4 to 8 day broth cultures of a proteolytic and hemolytic, Gram negative, motile organism, of intestinal origin and considered as belonging to the colon group were very active in lysing red blood cells and in digesting gelatin.
In filtrates heated to 55°C., for 5 minutes the hemolysin was destroyed, while the proteolysin was destroyed only after 30 minutes at that temperature.
In absorption experiments it was found that by incubation of the active filtrate with red blood cells at low temperature it was possible to absorb and remove all of the hemolysin without marked decrease in proteolytic activity of the filtrate.
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