Using different curing methods to determine resistance of antibiotics in streptococcus pyogenes

Fifteen isolates of Streptococcus pyogenes was isolated and activated from tonsillitis in Muqdadiya city/Iraq. The sensitively of these isolates have been tested against (15) antibiotics. The results showed that highest resistance among Amikacin, Ampicillin and Trimethoprim with percentage 100%, while the lowest resistance was recorded for Penicillin, Imipenem, Chloramphenicol and Vancomycin with 0%. Results of investigation of some virulence factors of S.pyogenes indicate that all isolates produce hemolysin enzyme with 100% and that all isolates surrounded by capsule with percentage 100% and uncapable to producing bacteriocins, while (14) isolates (93.3%) are able to Dnase producer, whereas (13) isolates (86.6%) were Bio film producer, in addition to (11) isolates (73.3%) had the ability to produce cysteine protease enzyme, on other hand (9) isolates (60%) were able to streptokinase production. The results of plasmid content indicate that all isolates contain single large plasmid band. Curing of plasmids was conducted by use of three materials included acridine orange, ethidium bromide and sodium dodecyl sulfate, the acrdine orange showed strongest curing material and the plasmid lost at concentration (256 µg/ml) and plasmid lost at by ethidium bromide with concentration (512 µg/ml), whilst sodium dodecyl sulfate was the weaker material and the plasmid lost at concentration (2000 µg/ml).