Overview
- The study published in PNAS in July 2026 analysed nearly 2,800 Campylobacter genomes from chickens and wild birds collected across 30 countries between 1979 and 2024 and found more than a 100‑fold increase in movement of strains into commercial flocks.
- Mathematical models in the paper show that once poultry populations reach a critical scale, Campylobacter strains originating in wild birds can become self‑sustaining inside large commercial flocks even if they were previously poorly adapted to chickens.
- Genomic analyses identified genetic changes linked to survival in poultry, including genes tied to antimicrobial resistance, oxidative stress tolerance, metal uptake and motility, which could make some human infections harder to treat.
- The findings sharpen public‑health concerns because Campylobacter is the leading bacterial cause of gastroenteritis in the UK with roughly 70,000 reported cases last year and previous Oxford work linked about 80% of local human infections to poultry meat.
- Authors and experts say the results call for tighter farm biosecurity, stricter controls on antibiotic use in livestock, and expanded surveillance of bacterial genomes while separate claims that Campylobacter drives cancer progression remain preliminary and need more validation.