Fig. 12

The mechanism considered for the third case study is antibiotic resistance (R) plasmid transfer across bacterial cells, recapitulating the basic conjugation mechanism modeled in [59]. The plasmid transfer mechanism [60] begins with a Donor cell that carries a conjugative R plasmid (top left). The Donor extends a Pilus, a proteinaceous protrusion [61] to contact a compatible receiver cell, named the Transconjugant cell (top right). In this example, the Pilus is encoded in the R plasmid. Upon contact, the Pilus retracts, pulling the cells together and establishing a conjugation bridge. This bridge enables the transfer of one of the plasmid DNA strands in linearized form from the Donor to the Transconjugant (center). At this point, both cells hold a single-stranded copy of the R plasmid. Finally, both cells build the second strand for their respective R plasmid copies through circularization and DNA synthesis. Thus, both Donor and Transconjugant cells are equipped to disseminate the R plasmid further, making them both Donor cells (bottom) enacting antibiotic resistance propagation