A membrane-depolarizing toxin substrate of the type VII secretion system mediates intraspecies competition.

The type VII protein secretion system (T7SS) is conserved across strains and plays important roles in virulence and interbacterial competition. To date, only one T7SS substrate protein, encoded in a subset of genomes, has been functionally characterized. Here, using an unbiased proteomic approach, we identify TspA as a further T7SS substrate.

Recombination-mediated remodelling of host-pathogen interactions during niche adaptation.

Large-scale recombination events have led to the emergence of epidemic clones of several major bacterial pathogens. However, the functional impact of the recombination on clonal success is not understood. Here, we identified a novel widespread hybrid clone (ST71) of livestock-associated that evolved from an ancestor belonging to the major bovine lineage CC97, through multiple large-scale recombination events with other lineages occupying the same ruminant niche.

Structural basis for intrinsic thermosensing by the master virulence regulator RovA of Yersinia.

Pathogens often rely on thermosensing to adjust virulence gene expression. In yersiniae, important virulence-associated traits are under the control of the master regulator RovA, which uses a built-in thermosensor to control its activity. Thermal upshifts encountered upon host entry induce conformational changes in the RovA dimer that attenuate DNA binding and render the protein more susceptible to proteolysis.

Genomic variations define divergence of water/wildlife-associated Campylobacter jejuni niche specialists from common clonal complexes.

Although the major food-borne pathogen Campylobacter jejuni has been isolated from diverse animal, human and environmental sources, our knowledge of genomic diversity in C. jejuni is based exclusively on human or human food-chain-associated isolates. Studies employing multilocus sequence typing have indicated that some clonal complexes are more commonly associated with particular sources.