Temporal Variation and Host Association in the Campylobacter Population in a Longitudinal Ruminant Farm Study

Abstract

ABSTRACTCampylobacter jejuniandC. coliwere quantified and typed, using multilocus sequence typing (MLST), from fecal samples collected from a mixed cattle and sheep farm during summer. Cattle had a significantly higher prevalence than sheep (21.9% [74/338] and 14.0% [30/214], respectively), but both decreased over time. There were no differences in the averageCampylobacterconcentrations shed by cattle (600 CFU g−1) and sheep (820 CFU g−1), although sheep did show a significant temporal reduction in the number ofCampylobacterorganisms shed in their feces. A total of 21 different sequence types (STs) (97.7%C. jejuni, 2.3%C. coli) were isolated from cattle, and 9 different STs were isolated from sheep (40.6%C. jejuni, 59.4%C. coli). TheCampylobacterpopulation in cattle was relatively stable, and the frequencies of genotypes isolated showed little temporal variation. However, the composition of subtypes isolated from sheep did show significant temporal differences. The cattle and sheep consistently showed significant differences in their carriage ofCampylobacterspecies, STs, and CCs despite the fact that both were exposed to the same farming environment. This work has highlighted the patterns of aCampylobacterpopulation on a ruminant farm by identifying the existence of both temporal and between-host variations.