Virulence gene profiles, SCCmec types, integrons, and antimicrobial resistance of clinical Staphylococcus aureus isolates from Yasuj, southwest Iran

Authors

  • Sahar Milani Department of Medical Microbiology, Yasuj University of Medical Sciences, Yasuj, Iran
  • Hadi Ebrahimi Student Research Committee, Yasuj University of Medical Sciences, Yasuj, Iran
  • Seyed Sajjad Khoramrooz Cellular and Molecular Research Center, Yasuj University of Medical Sciences, Yasuj, Iran
  • Leila Manzuri Social Determinants of Health Research Center, Yasuj University of Medical Sciences, Yasuj, Iran
  • Marjan Salahi Department of Medical Microbiology, Yasuj University of Medical Sciences, Yasuj, Iran
  • Seyed Abdolmajid Khosravani Cellular and Molecular Research Center, Yasuj University of Medical Sciences, Yasuj, Iran
  • Kasra Sharifi Student Research Committee, Kazerun Branch, Islamic Azad University, Kazerun, Iran
  • Asghar Sharifi Cellular and Molecular Research Center, Yasuj University of Medical Sciences, Yasuj, Iran

DOI:

https://doi.org/10.18502/ijm.v18i5.22864

Keywords:

Staphylococcus aureus; Virulence factors; Antibiotic resistance; Public health; Iran

Abstract

Background and Objectives: Staphylococcus aureus poses clinical challenges through its virulence and antibiotic resis- tance, including SCCmec-mediated methicillin resistance. Integrated data on virulence profiling, molecular typing, and resistance are limited in Southwest Iran. We characterized virulence genes, SCCmec types, integrons, and antimicrobial resistance in S. aureus from diverse clinical sources in Yasuj, Iran.

Materials and Methods: We analyzed 214 S. aureus isolates recovered from tonsil, wound, sinus, and blood specimens (2020–2023). Species confirmation was by nuc PCR. Antimicrobial susceptibility testing followed CLSI disk diffusion guidelines; MRSA was confirmed by mecA PCR. PCR assays detected hemolysin genes (hla, hlb, hld), toxin genes (tst, pvl, eta, etb, etd), MSCRAMM genes (sdrC, sdrD, sdrE), sak, integrase genes (intI, intII), and SCCmec types I, III, and IVa. Results: Isolates were from tonsils (59.8%), wounds (29.9%), sinusitis (6.1%), and blood (4.2%). MRSA prevalence was

29.0%. Highest resistance was to penicillin (98.6%), erythromycin (59.3%), and tetracycline (54.7%), with MDR in 32.7%. Prevalent virulence genes were hld (87.9%), hla (68.2%), sak (60.3%), sdrC (44.4%), eta (37.9%), sdrD (36.9%), tst (32.2%), sdrE (29.0%), etd (18.2%), and pvl (3.7%). Among 104 MDR/MRSA isolates, intI and intII were found in 14.4% and 10.6%. SCCmec type III dominated (80.5%), followed by I (14.5%) and IVa (5.0%); types I and III were significantly linked to MDR (P < 0.05). Four isolates co-harbored pvl, tst, and hla.

Conclusion: Considerable virulence gene carriage and SCCmec type III dominance were observed. Gentamicin, ciproflox- acin, cotrimoxazole, and clindamycin remain effective. Coexistence of life-threatening toxin genes and high resistance rates necessitates enhanced infection control.

Published

2026-10-04

Issue

Volume (18) issue (5)

Section

Articles