DNA conjugation is a contact-dependent horizontal gene transfer mechanism responsible for the dissemination of metabolic properties in bacteria, including drug resistance. Despite several decades of extensive investigation since its initial discovery in the 1940s1, a comprehensive understanding of the dynamics of conjugation at the cellular scale is still missing2. In our laboratory, we use live-cell microscopy combined with specific genetic reporters to dissect the dynamics of conjugation in real-time, providing insights into its progression, intracellular organization, and regulation in space and time.

This seminar will encompass several recent advancements derived from our research, which shed light on the sequential plasmid processing during transfer from donor to recipient cells, the timing of plasmid-encoded protein production in the host cell, the functional significance of exclusion systems responsible for preventing self-transfer, and a novel perspective on the role of the conjugative pilus in mediating distant plasmid transfer3-6. These studies reveal the strategy employed by conjugative plasmids to ensure their efficient dissemination and stable establishment.

References:

1. Lederberg, J., and Tatum, E.L. (1946). Gene recombination in Escherichia coli. Nature 158, 558.

2. Virolle, C., Goldlust, K., Djermoun, S., Bigot, S., and Lesterlin, C. (2020). Plasmid Transfer by Conjugation in Gram-Negative Bacteria: From the Cellular to the Community Level. Genes (Basel) 11, 1239. 10.3390/genes11111239.

3. Nolivos, S., Cayron, J., Dedieu, A., Page, A., Delolme, F., and Lesterlin, C. (2019). Role of AcrAB-TolC multidrug efflux pump in drug-resistance acquisition by plasmid transfer. Science 364, 778–782. 10.1126/science.aav6390.

4. Couturier, A., Virolle, C., Goldlust, K., Berne-Dedieu, A., Reuter, A., Nolivos, S., Yamaichi, Y., Bigot, S., and Lesterlin, C. (2023). Real-time visualisation of the intracellular dynamics of conjugative plasmid transfer. Nat Commun 14, 294. 10.1038/s41467-023-35978-3.

5. Goldlust, K., Couturier, A., Terradot, L., and Lesterlin, C. (2022). Live-Cell Visualization of DNA Transfer and Pilus Dynamics During Bacterial Conjugation. Methods Mol Biol 2476, 63–74. 10.1007/978-1-0716-2221-6_6.

6. Kelly Goldlust, Adrien Ducret, Manuel Halte, Annick Dedieu-Berne, Marc Erhardt, and Christian Lesterlin (2023). The F pilus serves as a conduit for the DNA during conjugation between physically distant bacteria. Proc Natl Acad Sci U S A. 2023 Nov 21;120(47):e2310842120. doi: 10.1073/pnas.2310842120. Epub 2023 Nov 14. PMID: 37963249