Isolation, Cloning, and Expression of Streptococcus dysgalactiae Subspecies Superantigen by SDS-PAGE in Psoriasis Patients

Abstract

Background and Objective: Streptococci are Gram-positive and anaerobic bacteria that are isolated from different sources. These bacteria are capable of producing superantigens, toxins, and biologically-active substances and are therefore very important in the field of infectious disease. Streptococcal pyrogenic exotoxins A (speA) is produced by various bacteria, including Streptococcus dysgalactiae. This study aimed at the isolation, cloning, and production of speA from streptococci from the skin of psoriasis patients. Methods: In this descriptive-laboratory study, samples were taken from 60 psoriasis patients. S. dysgalactiae isolated were identified by different tests. The speA gene was cloned by the TA cloning method using PTG-19 vector into the Escherichia coli X11 blue as host. Expression of the cloned gene in recombinant colonies was evaluated by SDS-PAGE. Results: Screening of white recombinant colonies confirmed the presence of speA genes. Expression of the speA gene in E. coli X11 blue was confirmed by SDS-PAGE. Conclusion: Streptococcus superantigens can be considered as a rich source of vaccine production for different infections caused by these bacteria. By utilizing different cloning hosts and investigating optimal production conditions, S. dysgalactiae could be a candidate for future studies on vaccine production.

Keywords

• streptococcus dysgalactiae
• escherichia coli
• spea gene
• cloning
• superantigens
• sds-page