CLONAL DIVERSITY, VIRULENCE, AND ANTIMICROBIAL RESISTANCE OF STAPHYLOCOCCUS AUREUS ISOLATED FROM PATIENTS WITH SKIN AND SOFT TISSUE INFECTIONS FROM A PRIVATE TERTIARY TEACHING AND REFERRAL HOSPITAL IN KENYA

Authors

  • Ephantus Mbugua Author
  • Rabecca Barasa Author
  • Catherine Mwangi Author
  • Stanley Onyango Author
  • Geoffrey Omuse Author
  • Revathi Gunturu Author
  • Johnstone Kinyua Author

Abstract

Background: Staphylococcus aureus (S. aureus) remains a significant global health concern because of its strong virulence factors and ability to develop antimicrobial resistance (AMR).
Objective: This study investigated the clonal diversity, virulence, and
antimicrobial resistance of S. aureus isolated from patients with skin and soft tissue infections (SSTIs) at a Private Tertiary Teaching and Referral Hospital in Kenya.
Methods: This was a cross-sectional study conducted between October 2019 and November 2020. Wound specimens were cultured for S. aureus and tested for antimicrobial susceptibility using the VITEK® 2 platform. Deoxyribonucleic acid (DNA) was sequenced using a MinION Mk1B sequencer. Resistance genes were identified using ResFinder and ARIBA, and virulence genes were screened using Virulence Finder.
Results: Out of 327 specimens, 98 (30.0%) were positive for S. aureus. Among these, methicillin-resistant S. aureus (MRSA) accounted for 16 (16.3%) of the isolates. Resistance was highest to penicillin (90.8%), followed by trimethoprim/sulfamethoxazole (63.2%). Whole-genome sequencing confirmed the presence of key resistance and virulence determinants in MRSA, with a high concordance (≥87.5%) between genotypic and phenotypic profiles. Regarding molecular characterization, isolate typing revealed four clonal complexes, nine sequence types (STs), ten staphylococcal protein A (spa) types, and three staphylococcal cassette chromosome mec (SCCmec) types.
Conclusion: The study reveals the emergence of highly virulent and multidrugresistant MRSA clones in Kenya. By uncovering the evolving genetic landscape of S. aureus, the study provides critical evidence to inform antimicrobial stewardship and regional genomic surveillance in East Africa.

Author Biographies

  • Ephantus Mbugua

    Technical head, Molecular section Aga Khan University Hospital; P.O Box 30270- 00100, Johnstone Kinyua; Dean School of Biomedical Sciences, Jomo Kenyatta University of Agriculture and Technology (JKUAT); P.O Box 62000-00200

  • Rabecca Barasa

    Research Assistant Aga Khan University Hospital; P.O Box 30270-00100

  • Catherine Mwangi

    Lecturer, Department of Medical Microbiology and Parasitology, School of Health Sciences, Kenyatta University; P. O Box 43844-00100

  • Stanley Onyango

    Post-doctorate, Research Fellow, Aga Khan University Hospital; P. O Box 30270- 00100

  • Geoffrey Omuse

    Associate Professor and Consultant Clinical Pathologist Aga Khan University Hospital; P. O Box 30270-00100

  • Revathi Gunturu

    Associate Professor and Consultant Clinical Microbiologist Aga Khan University Hospital; P.O Box 30270-00100

  • Johnstone Kinyua

    Dean School of Biomedical Sciences, Jomo Kenyatta University of Agriculture and Technology (JKUAT); P.O Box 62000-00200

References

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Published

2025-12-19

Issue

Vol. 102 No. 8 (2025): East African Medical Journal Vol.102 No. 8 (2025)

Section

Original Article