Production of proteinase by hemolytic streptococci in various clinical conditions.

The proteinase activity of strains of group A streptococci isolated from patients in acute and convalescent phases of illness was found to be remarkably constant. Sulfadiazine therapy of patients did not affect proteinase production by the infecting streptococci. The ability to produce streptococcal proteinase would appear to be related to the strain and not necessarily to the serological type. No relationship could be found between the capacity of group A streptococci of different serological types to produce proteinase and the various clinical responses to infection with these microorganisms.