Abstract
OBJECTIVE: This study aimed to comprehensively investigate the antibiotic resistance characteristics of Staphylococcus aureus (S. aureus) in chronic rhinosinusitis (CRS) patients and to identify key determinants influencing the development of methicillin-resistant Staphylococcus aureus (MRSA) infections. METHODS: A retrospective analysis was conducted on 180 CRS patients admitted to our hospital between February 2022 and July 2024. Nasal secretion samples were collected upon admission for S. aureus strain isolation, and antibiotic susceptibility testing was performed using an automated microbiology system. Patients were categorized into MRSA and methicillin-sensitive Staphylococcus aureus (MSSA) groups based on oxacillin resistance. Univariate analysis was used to screen potential risk factors, followed by multivariate logistic regression to determine independent predictors. RESULTS: Among 180 isolated S. aureus strains, 74 (41.1%) were MRSA and 106 (58.9%) were MSSA. MRSA strains exhibited significantly higher resistance rates to cefoxitin, amikacin, ciprofloxacin, and six other antibiotic classes compared to MSSA strains (all P<0.05), with resistance exceeding 50% for fluoroquinolones and macrolides. Univariate analysis identified 12 clinical factors associated with MRSA infection, including male sex, smoking history, disease duration >5 years, and frequent antibiotic use. Multivariate regression analysis confirmed nine independent risk factors: male sex (OR=2.31), nasal structural abnormalities (OR=1.89), previous nasal surgery (OR=1.76), ≥3 acute infections per year (OR=2.14), excessive antibiotic exposure, and others. CONCLUSION: MRSA exhibits pronounced resistance to commonly used antibiotics in CRS treatment. Clinicians should prioritize targeted screening for high-risk patients, optimize antibiotic stewardship, and enhance postoperative nasal function management. Implementing a multifaceted approach-including early risk assessment, standardized antibiotic use, and intensified follow-up care-can effectively mitigate MRSA infection risks and improve overall treatment outcomes for CRS patients.