High prevalence of methicillin resistant and enterotoxin gene-positive Staphylococcus aureus among nasally colonized food handlers in central Iran

  • Saeed Fooladvand
  • Hossein Sarmadian
  • Danial Habibi
  • Alex van Belkum
  • Ehsanollah Ghaznavi-RadEmail author
Original Article


This study defined the prevalence of enterotoxin gene-positive Staphylococcus aureus strains among food handlers and non-food processing healthy nasal S. aureus carriers in central Iran. Meticillin-resistant S. aureus (MRSA) strains were diagnosed by cefoxitin disk diffusion. PCR was used to detect the mecA, Sa442, and enterotoxin genes. Out of the 1113 food handlers, 224 (20.1%) were nasal carriers of S. aureus and 157 (70.1%) of these isolates were positive for one or more enterotoxin genes. The most prevalent enterotoxin gene was sei (40.2%), followed by seg (35.3%), sea (23.5%), seb (15.2%), sec (5.5%), and seh (2.7%). See and sed genes were not found. Sixty seven (42.7%) of enterotoxin gene-positive isolates possessed a single enterotoxin gene, and 64 (40.8%), 23 (14.7%), and 3 (1.9%) contained two, three, or four enterotoxin genes, respectively. The most frequently detected gene combination was sei/seg (n = 35, 22.3%). Thirty seven (16.5%) isolates were diagnosed as MRSA, and 27 (73%) of these strains were positive for at least one enterotoxin gene. Out of 546 healthy controls, 100 individuals were identified as S. aureus nasal carriers; among the strains, 39 (39%) were positive for at least one enterotoxin gene. Only one (1%) CA-MRSA was identified among the strains from the volunteers. A high prevalence of meticillin resistant and enterotoxin-positive S. aureus were documented in food handlers. We suggest that this may be due to the frequent handling of contaminated foodstuffs and that this is possibly related to the elevated frequencies of acquired staphylococcal food poisoning in this population.


Nasal carriage Staphylococcus aureus Enterotoxin genes Food handlers 



This paper is extracted from the thesis by Saeed Fooladvand to fulfill the requirement for a Master of Sciences in medical bacteriology at Arak University of Medical Sciences, Iran.

Funding information

This work was conducted with financial assistance from Arak University of Medical Sciences, Iran. Authors would like to appreciate this contribution.

Compliance with ethical standards

Conflict of interest

The authors declare that they have no conflict of interest.


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Copyright information

© Springer-Verlag GmbH Germany, part of Springer Nature 2018

Authors and Affiliations

  • Saeed Fooladvand
    • 1
  • Hossein Sarmadian
    • 2
  • Danial Habibi
    • 3
  • Alex van Belkum
    • 4
  • Ehsanollah Ghaznavi-Rad
    • 1
    • 5
    Email author
  1. 1.Department of Medical Microbiology, Faculty of MedicineArak University of Medical SciencesArakIran
  2. 2.Department of Infectious DiseasesArak University of Medical SciencesArakIran
  3. 3.Department of Biostatistics, Faculty of MedicineArak University of Medical SciencesArakIran
  4. 4.Data Analytics UnitBioMérieuxLa Balme les GrottesFrance
  5. 5.Molecular and Medicine Research Center, Faculty of MedicineArak University of Medical SciencesArakIran

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