Contributions of whole-genome sequencing to the epidemiological monitoring of <i>Campylobacter</i> spp. in France

ABSTRACT Next-generation sequencing techniques have revolutionized the epidemiology and understanding of Campylobacter spp. infections. In this study, we present the results of a next-generation sequencing (NGS) analysis conducted in 2024 on 2,360 Campylobacte r spp. strains isolated in France, including 1,959 Campylobacter jejuni, 358 Campylobacter coli , and 43 Campylobacter fetus strains. We describe the diversity of circulating strains and provide an overview of the main mechanisms of antibiotic resistance. We identified a variety of resistance mechanisms, particularly for resistance to group A penicillins. Notably, we identified a novel promoter upstream of the gene encoding a beta-lactamase. Using source attribution markers for C. jejuni and C. coli, we identified poultry as the main vector for infections by these two species. However, ruminant meat accounts for a significant proportion of C. jejuni infections in France. This study demonstrates how a sequencing strategy can generate large-scale and high-resolution data for understanding Campylobacter spp. infections.