Impact: These findings may help to identify genetic regions associated with IMPC risk.

This study aimed to determine the genetic regions associated with strain effects on lesion area.

In particular, the oldest pre-epidemic isolates carry phage-associated genetic regions not previously reported in S. Enteritidis.

The genomic positions of recombinant and mobile genetic regions were partially linked, suggesting their concurrent occurrence.

Further research on these genetic regions will enhance our understanding of the genetic basis of natural menopause.