Multiple isolation of ST398/t011 MRSA from patients in the first half of 2025 in Imam Reza Hospital, Bojnurd, North Eastern Iran

Abstract

Introduction

Methicillin-resistant Staphylococcus aureus (MRSA) remains a global health threat, with livestock-associated (LA-)MRSA ST398/t011 emerging in regions with human-animal contact. This study reports the first detection of ST398/t011 in clinical isolates from Bojnurd, northeastern Iran, alongside the hospital-associated ST239/t037 clone.

Methods

From January to April 2025, 242 clinical samples from Imam Reza Hospital were screened for S. aureus. MRSA isolates underwent antimicrobial susceptibility testing (CLSI M100-2023) and molecular characterization (mecA, mecC, vanA, cfr, PVL, tsst, sec, hla; SCCmec, agr, spa typing, MLST).

Results

Of 32 positive cultures, 7 MRSA isolates were identified (ST398/t011 [n = 4]; ST239/t037 [n = 3]). All harbored mecA and exhibited resistance to β-lactams, clindamycin, and gentamicin but remained susceptible to vancomycin/linezolid. The PVL gene was detected in one ST398/t011 isolate. ST398/t011 carried SCCmec V and agr I, while ST239/t037 had SCCmec III. Isolates were recovered from wound (n = 3), blood (n = 2), eye (n = 1), and urine (n = 1) samples, with patients aged 6–48 years.

Discussion

This first report of LA-MRSA ST398/t011 in northeastern Iran highlights potential zoonotic transmission risks in this agricultural region. Co-detection of PVL in ST398/t011 and multidrug-resistant ST239/t037 underscores the need for enhanced surveillance. Limitations include the small sample size, but findings warrant further One Health investigations to assess reservoirs and transmission dynamics.