Prevalence and Molecular Typing of Methicillin-Resistant Staphylococcus aureus in Healthcare Workers and Patients in Federal Medical Centre Yola, Adamawa State

Methicillin-resistant Staphylococcus aureus (MRSA) colonization in healthcare workers is a recognized source of patient infection in hospital settings, yet the molecular epidemiology of MRSA transmission between healthcare workers and patients in North East Nigerian hospitals has not been studied. This study determined the prevalence of MRSA nasal carriage in healthcare workers and patients at Federal Medical Centre Yola, Adamawa State, and applied molecular typing to investigate transmission dynamics. Nasal swabs from 120 healthcare workers and 120 patients were processed for S. aureus isolation on mannitol salt agar. Isolates were confirmed by coagulase test and PCR for mecA gene. MRSA isolates were spa-typed, and virulence genes including PVL (lukS-PV, lukF-PV) were detected by PCR. Clonal relationships were assessed by multilocus sequence typing (MLST) for selected isolates. MRSA nasal carriage prevalence was 18.3 percent in healthcare workers and 12.5 percent in patients. spa typing identified 12 distinct spa types, with t037 as the dominant type in both groups. Shared spa types between healthcare workers and patients in the same ward were identified in 35.3 percent of matched cases, suggesting intra-ward transmission. PVL genes were detected in 14.5 percent of healthcare worker isolates and 8.3 percent of patient isolates. MRSA ST239 was confirmed as the predominant clonal lineage. These findings provide molecular evidence of healthcare worker-to-patient MRSA transmission in Adamawa State and support targeted decolonization and strict contact precaution protocols for MRSA-positive healthcare workers. Keywords: MRSA, nasal carriage, healthcare workers, spa typing, Adamawa.