Quantifying the Consequences of New Plasmid Acquisition

Conjugative plasmids drive genetic diversity and evolution in microbial populations, significantly contributing to community function. Controlling where and when plasmids spread within these populations has important applications in environmental, agricultural, and clinical settings. Previous studies have primarily focused on the plasmid fitness cost as a determinant of plasmid outcomes: strains bearing high-cost plasmids are either out-competed or evolve compensatory mutations that ameliorate the plasmid’s metabolic burden. However, acquiring a plasmid also introduces an immediate, but transient, disruption to metabolism – a plasmid acquisition cost – that impacts population growth dynamics. The impacts of these short-term effects on growth and plasmid prevalence are a widely unknown, yet critical feature of conjugation dynamics. Here I will discuss our recent work focused on quantifying and understanding plasmid acquisition costs across various genetic, environmental, and ecological contexts. Ultimately, such understanding has implications in developing novel methodologies for rational microbial community prediction and design.