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  • Identification of Staphylococcus aureus enterotoxin genes of seb and tsst toxin from the nose of sheep in Sistan region by PCR method
  • Saeedeh Sarani,1,* Ahmad Rashki,2 Saeed Salri,3 Mohsen Najimi,4
    1. Zabul University


  • Introduction: Staphylococcus aureus is known to be a common cause of food poisoning and is also seen as a natural flora in humans and animals. Staphylococcus aureus produces several extracellular enterotoxins, which is regarded one of the key virulence factors of this bacterium and has extremely important effects on its host. It colonizes the anterior portion of the nasal passages and raises the risk of staphylococcal infections. Because each enterotoxin causes a distinct disease and shares numerous antigenic similarities with other enterotoxins, for instance, enterotoxins are responsible for food poisoning and the TSST-1 toxin is responsible for toxic shock syndrome. The toxin released by this bacterium can be identified using a variety of techniques. One of these methods is the PCR test, which is very sensitive and fast and very specific. This research was carried out with the aim of identifying the enterotoxin genes (SEB, TSST-1) of Staphylococcus aureus by multiplex PCR method.
  • Methods: In this work, sheep nasal swab samples were collected from livestock farms in the Sistan region in order to identify the enterotoxin genes of Staphylococcus aureus. 100 strains of Staphylococcus aureus were identified and verified by biochemical assays out of 300 strains found in sheep's samples. After that, bacterial DNA was extracted by boiling, and the DNA concentration was measured using a Nano drop device. The extracted samples were then kept at a low temperature until PCR tests were run, which were then used to identify the genes for Staphylococcal enterotoxin B (seb) and tsst-1 toxin (tsst), using multiplex PCR. The seA and seC genes' PCR products were examined using an Agarose gel at a concentration of 1.5%.
  • Results: 100 samples were verified after Staphylococcus aureus were cultured and isolated. To detect the enterotoxin gene and the Staphylococcus aureus toxin gene in sheep nasal samples collected from livestock farms in the Sistan region is the goal of this investigation. Out of 100 positive samples, 20% tested positive for the seb gene and 37% tested positive for the tsst gene. The results of this investigation demonstrated that the seC gene is more sensitive to detecting Staphylococcus aureus enterotoxin.
  • Conclusion: Staphylococcus aureus has been isolated from the nostrils of a sheep that appeared to be in good health; therefore PCR testing can be helpful for identifying bacteria that have the enterotoxin B genes and the sheep-specific TSST-1 toxin. In general, Staphylococcus aureus represents a possible health danger, especially when it is present in enterotoxigenic strains.
  • Keywords: Enterotoxin, Staphylococcus aureus, Sistan