show Abstracthide AbstractIn this project, we whole genome sequenced a large French isolate collection from different animal reservoirs, the environment and clinical cases, and contextualized these with published genomes. Systematic analysis using gene-by-gene comparison of 884 genomes of Campylobacter isolates, with a pan-genome list of genes, identified novel epidemiological markers to develop a novel source attribution approach. The loci selected as host-segregating markers were used to attribute the source of French and UK clinical Campylobacter isolates.