A comparative study on antibiotic resistance and virulence properties of Staphylococcus aureus isolated from hospitalized patients and hospital environment

  • Sareh Kholaseh
    Student Research Committee, Kurdistan University of Medical Sciences, Kurdistan, Sanandaj, Iran
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  • Safoura Derakhshan
    Address correspondence to Safoura Derakhshan PhD, Department of Microbiology, Faculty of Medicine, Kurdistan University of Medical Sciences, Kurdistan, Sanandaj, Iran.
    Liver and Digestive Research Center, Research Institute for Health Development, Kurdistan University of Medical Sciences, Kurdistan, Sanandaj, Iran

    Lung Diseases and Allergy Research Center, Research Institute for Health Development, Kurdistan University of Medical Sciences, Kurdistan, Sanandaj, Iran
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  • Masoumeh Abedini
    Department of Infectious Diseases, Kurdistan University of Medical Sciences, Kurdistan, Sanandaj, Iran
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Published:December 22, 2022DOI:


      • S. aureus strains isolated from the hospital environment were more resistant to antibiotics compared to clinical S. aureus isolates.
      • Clinical S. aureus showed more virulence compared to environmental S. aureus.
      • Integrons did not have a major role in the multidrug resistance of S. aureus in both patients and the environment.
      • Methicillin resistance was found in 11% of clinical S. aureus and 60% of environmental S. aureus.


      We compared the characteristics of clinical Staphylococcus aureus and S. aureus isolated from environmental surfaces in 3 hospitals.


      Clinical S. aureus isolates were collected from hospitalized patients. Environmental surfaces were sampled from the rooms of patients infected with S. aureus. After identifying rooms with the target organism, 3-5 high-touch surfaces in patient care areas were sampled using swabs before room cleaning by environmental services. S. aureus isolates were subjected to genotyping, antimicrobial susceptibility testing, and virulence determinant screening. The isolates were analyzed for integron content and sequences of variable region amplification products.


      There were epidemiologically unrelated 79 clinical and 62 environmental S. aureus isolates. Overall, 11.4% of clinical and 59.7% of environmental isolates were methicillin-resistant. The environmental and clinical S. aureus exhibited very different virulence profiles: 79% of the environmental isolates were negative for virulence genes compared to 2.5% of clinical isolates (P < .001). Environmental isolates were more resistant to antibiotics compared to clinical isolates. Class 1 integrons were only detected in 7 of 62 environmental isolates, of which 3 isolates had integrons with cysteine synthase cassette, 1 had aadA1, and 1 had an unknown cassette.


      These data indicate the different characteristics between environmental and clinical S. aureus, which may reflect different reservoirs from which the 2 groups acquired the strains.

      Key Words


      EN (environmental), CL (clinical)
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