Determine the timing and stage dependence of conjugation

Determine when conjugative DNA transfer occurs during Escherichia coli growth and biofilm formation and establish whether conjugation depends on growth phase or biofilm stage, including within the stages of multicellular self-organization.

Background

Conjugation can occur between physically connected E. coli cells and within aggregates, potentially contributing to antibiotic resistance spread. Observations suggest limited conjugation in mature biofilm regions, implying earlier occurrence, but the exact timing and dependence on growth or biofilm stages are unresolved—particularly in the context of self-organization from single cells to attached dormant chains.