Campylobacter fetus is an important veterinary pathogen associated with reproductive disease in livestock and, less frequently, invasive infections in humans. Accurate characterization of Campylobacter fetus relies on complementary laboratory methodologies, including microbiological, phenotypic, molecular, genomic, immunological, and host–pathogen interaction methods. Together, these methods provide valuable information on bacterial diversity, pathogenicity, epidemiology, and antimicrobial resistance, supporting advances in research, diagnosis, and surveillance.

This Topical Collection aims to cover laboratory workflows for sample collection and processing, bacterial isolation and cultivation, phenotypic and molecular characterization, genomic analyses, host–pathogen interaction models, antimicrobial resistance characterization, molecular epidemiology, and other innovative methodologies relevant to Campylobacter fetus. Overall, this collection will provide a practical reference for researchers and diagnostic laboratories by bringing together standardized and visually demonstrated methods that support the integrated characterization of this pathogen within a One Health framework.