Romain Durand, Kévin T Huguet, Nicolas Rivard, Nicolas Carraro, Sébastien Rodrigue, and Vincent Burrus
Nucleic Acids Research, gkab204, doi:10.1093/nar/gkab204
The emergence of multidrug resistant bacteria is fuelled by diverse mobile genetic elements including genomic islands and conjugative plasmids that often carry many antibiotic resistance genes. Mobilizable genomic islands (‘MGIs’) such as Salmonella Genomic Island 1 (SGI1) confer resistance to a wide range of antibacterial agents, while IncC plasmids are large, broad-host-range, and globally distributed plasmids that contribute to the propagation of multidrug resistance genes. MGIs are usually thought of as relatively passive mobile genetic elements that await the arrival of a helper self-transmissible element (often a conjugative plasmid) for horizontal transfer. To accomplish this, MGIs need to excise from the host’s chromosome and be translocated through a pore encoded by their helper element. This study describes details of a genetic regulatory mechanism by which SGI1 actively associates itself with a conjugative lncC plasmid in order to undergo horizontal transfer.