Work

Long-term clonal dynamics of sequence type 72 among methicillin-resistant and methicillin-susceptible Staphylococcus aureus in Korea

Year: 2026

Type: article

Abstract: OBJECTIVES: Long-term clonal dynamics of Staphylococcus aureus remain incompletely characterized, particularly with respect to differences between methicillin-resistant (MRSA) and methicillin-susceptible (MSSA) populations. We analyzed the sequence type (ST) distribution of 800 S. aureus blood isolates collected in Korea between 1999 and 2018 using multilocus sequence typing. METHODS: Temporal trends of ST72 were examined separately for MRSA and MSSA isolates and compared using interaction-based modeling and annual percent change (APC) analyses. RESULTS: The distribution of STs differed between MRSA and MSSA and changed over time. Among MRSA isolates, ST5 remained a predominant lineage throughout the study period. ST72 accounted for 16.9% of all isolates and increased over time in both MRSA and MSSA populations. ST72 emerged earlier and expanded more steadily among MRSA isolates, whereas its appearance among MSSA isolates showed a later onset and greater interannual variability. Although temporal slopes did not differ significantly between populations, APC estimates indicated a steeper increase of ST72 among MSSA isolates. CONCLUSION: These findings demonstrate the long-term establishment of ST72 within the Korean S. aureus population and highlight distinct population-level expansion patterns between MRSA and MSSA.

Source: International Journal of Infectious Diseases

DOI: 10.1016/j.ijid.2026.108487