<prompt> Which toxin of streptococcus cause hemolysisStreptolysin OStreptolysin SStreptodornanseHyaluronidase  <response>: Streptococci produces two hemolysins - streptolysin O and S. Streptolysin S is an oxygen stable hemolysin and is responsible for the hemolysis seen around streptococcal colonies on the surface of blood agar plates. It is called streptolysin S as it is soluble in serum. It is a protein but is not antigenic. Reference: Textbook of Microbiology; Anathanarayan and panikers; 10th edition; Page no: 213 