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Updated: Nov 2, 2025
A Fluorescence-based Method to Study Bacterial Gene Regulation in Infected Tissues
Published on: February 19, 2019
High frequency of enterotoxin encoding genes of Staphylococcus aureus isolated from food and clinical samples
Fakhri Haghi1,2, Habib Zeighami3, Zeynab Hajiloo4
1Department of Microbiology, School of Medicine, Zanjan University of Medical Sciences, Zanjan, Iran.
Background:
Staphylococcus aureus is recognized as an important cause of food poisoning related to the consumption of raw, undercooked, or mishandled foods worldwide.
Methods:
A total of 90 individual meat samples and 200 clinical specimens were collected and investigated the frequency of S. aureus and classical enterotoxin genes. The samples were cultured on Baird-Parker and Mannitol salt agar and subjected for confirmatory biochemical tests and molecular detection of femA, sea, seb, sec, sed, and see genes.
Results:
A total of 31 (34.5%) meat samples and 81 (40.5%) clinical specimens were positive for the presence of S. aureus. These isolates were detected with slightly higher frequency in clinical specimens than food samples (P> 0.05). Furthermore, the frequency of S. aureus in raw meat (23.4%) was higher than that in cooked meat samples (11.1%) (P< 0.05). Staphylococcal enterotoxin (SE) genes were identified in 18 (58.1%) of 31 meat isolates and 42 (51.8%) of 81 clinical isolates. The frequency of SE genes (except see) in meat isolates was slightly higher than that in clinical isolates (P> 0.05). We found sea and see genes with higher frequency than others in both meat and clinical samples. Furthermore, 55.5% of meat isolates and 38.1% of clinical isolates possessed more than one se gene.
Conclusion:
Detection of enterotoxigenic S. aureus in clinical and raw meat samples shows a probable risk for public health. Therefore, intensive and continuous monitoring of potentially pathogenic S. aureus is strongly recommended in order to evaluate the human health risk arising from food consumption.
