Prevalence and subtype characterization of Campylobacter in ceca of commercial broiler chickens at processing - a 452 flock, seven-year survey.

Human Campylobacter infections have been associated with chicken and other poultry meat products. Environmental conditions such a temperature and season can affect Campylobacter recoverability from chicken meat products. In the presented study, we sought to investigate the relationship between ambient weather conditions and isolation of Campylobacter from chicken flocks, as well as the subtype of these isolates. Campylobacter was isolated from ceca of broilers collected in a commercial processing facility over seven years, representing 452 flocks. Isolates were subjected to whole genome sequencing and subtyping by multilocus sequence typing (MLST). Approximately 60% (269/452) of flocks sampled were positive for Campylobacter. There was no significant effect on the presence of detectable Campylobacter by month, season, temperature, or rainfall during grow-out or transportation. Sixty-eight different STs were detected; 45 C. jejuni and 23 C. coli. Diversity as measured by Shannon's diversity index was higher in the spring and fall than in mid-winter and summer. We concluded that in the warm temperate climate of the Southeastern U.S., seasonality does not affect the rate of Campylobacter isolation from broilers, but diversity of isolates was higher in the milder spring and fall seasons.