Genetic diversity and resistance profiles of MRSA in community and healthcare settings

This study aimed to characterize and compare methicillin-resistant Staphylococcus aureus (MRSA) strains isolated from community members and healthcare workers (HCWs) in Egypt using antibiotic susceptibility testing, mecA gene detection, SCCmec typing, and ERIC-PCR fingerprinting. A cross-sectional study was conducted between September 2024 and January 2025, during which 450 specimens were collected from Mansoura University Hospitals and the local community, where 71 specimens (30.8%) were confirmed as MRSA. MRSA prevalence was significantly higher among HCWs, 62.5% (50/80), than among community members, 14% (21/150). In general, antibiotic resistance rates were higher in HCW strains. All isolates were resistant to cefoxitin and sensitive to vancomycin. The methicillin-resistant phenotype of the 71 MRSA isolates was confirmed by positive mecA gene tests, with SCCmec Type III prevalent among healthcare workers and SCCmec Type IV predominating in the community. ERIC-PCR fingerprinting demonstrated the isolates’ genetic diversity. The dendrogram based on ERIC patterns showed distinct clusters between community and hospital strains, though with some overlap, suggesting possible transmission between the two populations. In conclusion, MRSA strains from HCWs displayed broader antibiotic resistance and greater clonal similarity, while community strains were more diverse and less resistant. The presence of intermixed clusters between community-acquired (CA-MRSA) and (HCW-MRSA) suggested a possible bidirectional transmission pathway, underscoring the blurring of epidemiological boundaries. These results underline the necessity of ongoing molecular surveillance and integrated infection control strategies to track the spread of MRSA in community and clinical settings.