Hanieh Sharifian - Department of Microbiology, Shahr-e-Qods Branch, Islamic Azad University, Tehran, Iran
Ali Mohammad Ahadi - Department of Genetics, Faculty of Science, Shahrekord University , Shahrekord, Iran.
Fatemeh Foroohi - Department of Microbiology, Shahr-e-Qods Branch, Islamic Azad University, Tehran, Iran
Taher Mohammadian - Department of Microbiology, Shahr-e-Qods Branch, Islamic Azad University, Tehran, Iran

Nowadays, bacterial toxins are considering as powerful therapeutic strategies against the pathogenic organisms and other medical application. Shiga toxin is one of the most studied bacterial toxins found in Shigella dysenteriae and some Escherichia coli serogroups. In this study we screened the presence of Shiga toxin۲ (Stx۲) genes between the bacteria isolated from the stool and urine samples of the patients affected by diarrhea. Stool and urine samples were cultivated and microbial and biochemical tests were carried out. Well test was optimized for detection of killer phenotype of the bacteria. Colony-PCR and real-time PCR was performed for confirmation of presence of the Stx۲ gene in the extracted genomic DNA of the isolated bacteria, and finally, SDS-PAGE was used for differential analysis of protein profile between killer and non-killer bacteria. We optimized in this study a rapid molecular method for screening of Shiga toxin ۲ gene. Our presented condition for assay is referable and confident. Also, we purified, detected and analyzed functionally, Shiga toxin ۲ peptide and recorded bacterial strains producing Stx۲ toxin. In the future, real-time PCR assays can be developed for detection of Enterobacteriaceae virulence genes, including Stx and other its groups. The current study demonstrate that the real-time PCR technique is rapid and simple to use, and it is a promising method for identify Enterobacteriaceae toxins in human samples.

Evaluation, Stx۲, Genes, Bacteria, patients