Antimicrobial Resistance Patterns of Staphylococcus aureus Isolated from Nasal Carriage in Medical Students, University of Jos, Plateau State

Nasal carriage of Staphylococcus aureus, particularly methicillin-resistant strains (MRSA), among medical students constitutes a critical infection control concern in clinical training environments. This cross-sectional study assessed the prevalence and antimicrobial resistance patterns of S. aureus nasal carriage among 200 medical students at the University of Jos, Plateau State, in the North Central geopolitical zone of Nigeria. Nasal swab samples were collected and processed on mannitol salt agar and blood agar. Confirmed S. aureus isolates were tested for methicillin resistance using cefoxitin disc screening per CLSI 2023 criteria. Antibiogram profiles were determined by the Kirby-Bauer method against a panel of 15 antibiotics. The overall nasal carriage rate of S. aureus was 38.5 percent. MRSA constituted 21 percent of confirmed S. aureus carriers. Students in clinical years demonstrated significantly higher MRSA carriage than pre-clinical students, implicating hospital exposure as a contributing factor. Multi-drug resistance was documented in 55 percent of MRSA isolates. Linezolid and vancomycin retained complete in-vitro efficacy. These findings advocate for pre-clinical MRSA decolonization protocols, enhanced hand hygiene education, and mandatory infection control training for medical students prior to clinical postings. Regular surveillance of healthcare worker nasal carriage is equally recommended. Keywords: MRSA, nasal carriage, medical students, Jos, antibiotic resistance.