Molecular identification and evaluation of Streptokinase activity among streptococcus pyogenes in relation to streptokinase genotype isolated from tonsillitis patients

About 100 throat swab samples were taken from a patient suffering from tonsillitis, and 60 were obtained through biochemical tests. Of these, 40 were identified as hemolytic, and 6 were identified as S. pyogenic. The ability of these six strains to produce streptokinase was evaluated. Among the six strains, the one with the most variable production degrees was S. pyogenes S30. Its activity was 0.35 U/mg. S. pyogenes S30 was selected to determine the optimal conditions for streptokinase production. The maximum amount of the enzyme was obtained after the strain was given a base medium containing glucose of 0.5%, a yeast extract of 1.5%, and an inoculum with a size of 10.4. The optimal conditions for streptokinase production were established by precipitation with a 45% saturation of ammonium sulfate. The resulting enzyme was then purified using a combination of ion exchange, gel filtration, and DEAE-Cellulose. After the last step, the enzyme's specific activity was increased to 54 U/mg. S. pyogenes was then analyzed using a PCR method to determine the presence of the pyogenes specific primer. The results indicated that the six production strains exhibited 100% positive bands.