The study aimed to identify sources of campylobacter in 10 housed broiler flocks from three United Kingdom poultry companies. Samples from (i) the breeder flocks, which supplied the broilers, (ii) cleaned and disinfected houses prior to chick placement, (iii) the chickens, and (iv) the environments inside and outside the broiler houses during rearing were examined. Samples were collected at frequent intervals and examined for Campylobacter spp. Characterization of the isolates using multilocus sequence typing (MLST), serotyping, phage typing, and flaA restriction fragment length polymorphism typing was performed. Seven flocks became colonized during the growing period. Campylobacter spp. were detected in the environment surrounding the broiler house, prior to as well as during flock colonization, for six of these flocks. On two occasions, isolates detected in a puddle just prior to the birds being placed were indistinguishable from those colonizing the birds. Once flocks were colonized, indistinguishable strains of campylobacter were found in the feed and water and in the air of the broiler house. Campylobacter spp. were also detected in the air up to 30 m downstream of the broiler house, which raises the issue of the role of airborne transmission in the spread of campylobacter. At any time during rearing, broiler flocks were colonized by only one or two types determined by MLST but these changed, with some strains superseding others. In conclusion, the study provided strong evidence for the environment as a source of campylobacters colonizing housed broiler flocks. It also demonstrated colonization by successive campylobacter types determined by MLST during the life of a flock.

Aims: To investigate whether Arcobacter spp. colonize the poultry-rearing environment or whether they are contaminants acquired during transportation and/or from the processing plant. Methods and Results: Samples were collected on poultry farms and in the processing plant during slaughter and dressing. Two cultural methods of detection were used. Isolates were identified to species level using a multiplexpolymerase chain reaction (m-PCR) method, either on the initial suspensions, or after enrichment, or on pure cultures of isolates. Of the 62 samples examined from poultry farms, arcobacters were found only outside the rearing sheds (in effluent sludge and stagnant water). Thirty-four samples were examined from the processing plant and 26 were positive for arcobacters. All the isolates were Arcobacter butzleri. Arcobacters were not found in any sample by direct plating nor by m-PCR on the initial suspensions, thus it was concluded that numbers were very low. Conclusions: Arcobacter spp. were not found in samples from the live birds and their immediate environment, but A. butzleri was found in effluent sludge and stagnant water outside the rearing sheds. However, A. butzleri is common in poultry abattoirs, and it appears that poultry carcasses are contaminated during processing. Significance and Impact of the Study: Arcobacters are not found inside poultry-rearing sheds, but are contaminants in the processing environment.