Ecology of Arcobacter species in chicken rearing and processing

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 multiplex-polymerase 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.