Quantification of water as a potential risk factor for cross-contamination with Salmonella, Campylobacter and Listeria in a poultry abattoir

Abstract

1. Water used in a modern poultry processing line was tested from October 2005 to June 2006 to determine the level of bacteria in an abattoir in Germany.

2. A total of 420 water samples were taken from 14 processing sites (PSs), at 10 times, and from three different hours of the working shift at three sampling hours (SHs) at 5:00 a.m. (SH 1), 9:00 a.m. (SH 2) and 12:00 a.m. (SH 3). Each sample was assessed for the aerobic plate count (APC) and the prevalence of Salmonella, Campylobacter, Listeria and Yersinia over 30 sampling weeks. The APC numbers of each PS from three SHs were compared, and the prevalence of Salmonella, Campylobacter, Listeria and Yersinia from each PS of three SHs was determined as well as change from the initial PS to the end of the processing line.

3. A total of 46 water samples were positive for Salmonella, 120 positive for Campylobacter and 4 positive for Listeria. None of the water samples was found to be positive for Yersinia. During the course of the day, the APC increased. Salmonella was mostly found during SH 1 (5 a.m.) in water from all PSs. A high number of Campylobacter were observed at SH 2 (9 a.m.) and SH 3 (12 a.m.) from all PSs.

4. The results show that water, which is still used in substantial amounts in present poultry processing technology, can serve as a carrier for Salmonella and Campylobacter.

5. The findings indicate that birds might progressively contaminate the equipment and become contaminated via the same equipment, that water at every processing position of the line constitutes a risk and that more attention should be paid to effective water management in the processing plan.

ACKNOWLEDGEMENTS

We thank the management of the poultry abattoir for their support and for the opportunity of taking samples. A. Hamidi worked on sampling, data analysis and drafting the paper. R. Fries worked on study design, data analysis and drafting the paper. A. Muschaller supported sampling activities in the abattoir. H. Irsigler and D. Jaeger carried out work in the laboratory. All authors read and approved the final version of the manuscript. K. Wolf worked on the statistical analysis of the results.