The global landscape of Campylobacter : genomic epidemiology, AMR trends, and the path to vaccine development

SUMMARY

Campylobacter species, particularly Campylobacter jejuni and Campylobacter coli , are leading causes of bacterial gastroenteritis worldwide, responsible for an estimated 500 million cases of acute diarrheal illness annually. Despite their global prevalence and association with severe post-infectious sequelae such as Guillain-Barré syndrome, no licensed vaccine exists, and the growing threat of antimicrobial resistance further complicates clinical management. This review synthesizes current knowledge on the epidemiology, genomic diversity, antimicrobial resistance mechanisms, and vaccine development strategies for Campylobacter species, with emphasis on global trends and public health relevance in the United States. Through a One Health lens, we examine transmission across human, animal, and environmental reservoirs, and highlight the role of integrated genomic surveillance in tracking clonal expansion, horizontal gene transfer, and resistance dissemination. We also examine historical and current approaches to vaccine development, including whole-cell, subunit, glycoconjugate, and genomics-guided antigen discovery strategies. Challenges such as antigenic variability, phase variation, and inadequate experimental models have impeded progress, though recent genomics-informed interventions show promise in both poultry and human contexts. Continued investment in genomic surveillance, antimicrobial resistance, and rational antigen selection will be essential for developing effective vaccines and reducing the global burden of campylobacteriosis.