investigators will also stab several times through the agar using an inoculating loop. This stab allows for the detection of streptolysin O, a specific hemolysin produced by Streptococcus pyogenes.

The remaining cultures (Streptococcus pneumoniae, and Streptococcus pyogenes) will be taken from the blood agar plates inoculated in the previous ... after the addition of Zn this indicates a positive ...