Detection of livestock-associated MRSA ST398/t011 and hospital-associated MRSA ST239/t037 in a referral hospital in northeastern Iran: A six-month cross-sectional surveillance study (July-December 2025).

چکیده اصلی

BACKGROUND: Following initial detection of livestock-associated MRSA (LA-MRSA) ST398/t011 and hospital-associated MRSA (HA-MRSA) ST239/t037 in early 2025, we conducted a cross-sectional six-month surveillance study to determine whether these clones represent transient introductions or continued detection in a referral hospital in Bojnurd, North Khorasan Province, northeastern Iran. METHODS: From July to December 2025, we collected 258 consecutive clinical specimens at Imam Reza Hospital, Bojnurd. MRSA isolates underwent antimicrobial susceptibility testing, SCCmec typing, spa typing, and multilocus sequence typing. PCR detected genes encoding Panton-Valentine leukocidin (PVL), toxic shock syndrome toxin (TSST-1), and other virulence factors. Livestock exposure was defined using a structured questionnaire. RESULTS: Among 61 S. aureus isolates (23.6%), 11 (18.0%) were MRSA, all belonging exclusively to two previously identified clones: ST398/t011/SCCmec V/agr I (n = 6; 54.5%) and ST239/t037/SCCmec III/agr I (n = 5; 45.5%). Resistance patterns remained clone-specific, with all ST398 isolates resistant to tetracycline and trimethoprim/sulfamethoxazole. The PVL gene was detected in one ST398 isolate (16.7%). All ST239 isolates carried tst and sec. Livestock exposure was reported in 83.3% of ST398-infected patients. Clinically, all 11 patients survived; only one required ICU admission, and none experienced treatment failure. CONCLUSION: This study documents continued detection of LA-MRSA ST398/t011 at a referral hospital in Bojnurd, co-circulating with endemic HA-MRSA ST239/t037. The detection of a PVL-positive ST398 isolate warrants further investigation and underscores the importance of integrated One Health surveillance. Given the small sample size (n = 11), these findings are descriptive and hypothesis-generating rather than confirmatory.

متن کامل اصلی