title: Unraveling the regulatory network of IncA/C plasmid mobilization: When genomic islands hijack conjugative elements.
abstract: Conjugative plasmids of the A/C incompatibility group (IncA/C) have become substantial players in the dissemination of multidrug resistance. These large conjugative plasmids are characterized by their broad host-range, extended spectrum of antimicrobials resistance, and prevalence in enteric bacteria recovered from both environmental and clinical settings. Until recently, relatively little was known about the basic biology of IncA/C plasmids, mostly because of the hindrance of multidrug resistance for molecular biology experiments. To circumvent this issue, we previously developed pVCR94ΔX, a convenient prototype that codes for a reduced set of antibiotic resistances. Using pVCR94ΔX, we then characterized the regulatory pathway governing IncA/C plasmid dissemination. We found that the expression of roughly 2 thirds of the genes encoded by this plasmid, including large operons involved in the conjugation process, depends on an FlhCD-like master activator called AcaCD. Beyond the mobility of IncA/C plasmids, AcaCD was also shown to play a key role in the mobilization of different classes of genomic islands (GIs) identified in various pathogenic bacteria. By doing so, IncA/C plasmids can have a considerable impact on bacterial genomes plasticity and evolution.
authors.affiliation: Laboratory of Bacterial Molecular Genetics; Département de Biologie; Université de Sherbrooke ; Sherbrooke, Canada.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Carraro
authors.affiliation: Laboratory of Microbial Systems and Synthetic Biology; Département de Biologie; Université de Sherbrooke ; Sherbrooke, Canada.
authors.forename: Dominick
authors.initials: D
authors.lastname: Matteau
authors.affiliation: Laboratory of Bacterial Molecular Genetics; Département de Biologie; Université de Sherbrooke ; Sherbrooke, Canada.
authors.forename: Vincent
authors.initials: V
authors.lastname: Burrus
authors.affiliation: Laboratory of Microbial Systems and Synthetic Biology; Département de Biologie; Université de Sherbrooke ; Sherbrooke, Canada.
authors.forename: Sébastien
authors.initials: S
authors.lastname: Rodrigue
keywords: AcaCD; IncA/C plasmids; SGI1; Salmonella; Vibrio; antibiotic resistance; mobilizable genomic islands; pVCR94; regulation