Standardizing Molecular Detection of the entC Gene of Staphylococcus Aureus Isolated from Human Infections and Sequencing it

Document Type : Original Research

Authors

Baqiyatallah University of Medical Sciences

Abstract

Aims: The goal of this research is standardizing molecular detection of the entC gene of Staphylococcus aureus isolated from human infections and determining its sequence.
Methods: At first, the primer was prepared using the standard gene in the gene bank. Then, the molecular PCR method was set up to identify the entC gene in the Staphylococcus aureus bacteria extracted from human specimens (300 strains). The PCR product was sequenced and compared with the standard gene. Also, the ability of all entC gene carrier strains to produce enterotoxin C was tested using an ELISA kit.
Results: The results showed that the molecular technique of PCR had been well set up with various primers, because, the first and second primer pairs easily amplified a 102bp and a 1223bp fragment, respectively. A comparison of the sequence of the 1223bp fragment with the reference gene showed 99% compliance. The translated form shows a difference in position 218 only where alanine had replaced valine. The results of the ELISA test for assessing the toxigenicity of all the strains carrying the entC gene showed that 37% of the strains contained the gene.
Conclusion: Not only coagulase positive Staphylococcus aureus strains but also coagulase negative strains produce superantigenic enterotoxins. This research provides a simple and fast method of detecting toxigenicity of the Staphylococcus aureus bacteria and a method of standardizing detection of enterotoxin C-producing strains, because the detection of superantigenic enterotoxins can be a very valuable help intreating patients infected with them and preventing further complications.

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