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The aim of this study was to indicate the prevalence of thermophilic Campylobacter, Listeria spp., Escherichia coli, Salmonella spp. and Yersinia enterocolitica in a sheep food chain in Brandenburg.
The study was performed from July 2008 to August 2009. A total of 321 samples was collected from 9 sheep farms, supplying their animals to the same slaughterhouse. Samples were examined using qualitative (for thermophilic Campylobacter, Listeria, E.coli, Salmonella and Yersinia) and quantitative methods (Aerobic Plate Count and Enterobacteriaceae Count for investigation of drinking water samples).
Thermophilic Campylobacter, Listeria spp. and Escherichia coli were identified from animal and environmental samples, with an average of 20.4%, 14.3% and 60.8%, respectively. Salmonella spp. and Yersinia enterocolitica were not found in any sample.
Campylobacter was most frequently identified in fecal samples (43.6%). Using conventional techniques, C.jejuni was predominantly found (66.7%), followed by C.coli (30.3%) and C.lari (3.0%). Using PCR, the majority of Campylobacter species was C.jejuni (35.3%), followed by C.lari (30.9%) and C.coli (26.5%).
The isolation rate of Listeria spp. was high in environmental samples (27%), whereas the percentage of animal samples accounted to 6.2%. The majority of Listeria isolates was L.monocytogenes (43.1%), while L.innocua, L.denitrificans, and L.ivanovii were found in a percentage of 23.5%, 13.7% and 9.8%, respectively.
Among animal samples, E.coli was predominantly isolated from fecal samples (97.1%). Among environmental samples, litter was the most contaminated sample type (100% positive).
Campylobacter strains were in some farms identical both in animal and environmental samples (7th, 9th and 12th excursion), which was discovered using PFGE techniques. Comparing the individual sheep farms, the same PFGE-types or subtypes were obtained also from different farms (PFGE-type K-6 in 6th, 7th and 9th excursion).
A total of 23 drinking water samples was collected, of them, 21 samples from 10 excursions were tested for Aerobic Plate Count (APC) and Enterobacteriaceae Count (EC). The mean APC (log10 CFU/ml) was 4.54. Campylobacter was identified in 8.7% (2/23) of drinking water samples, while all of them were free from Salmonella (in 10 ml). The E.coli isolation rate was 47.8% (11/23) in these samples.
In conclusion, thermophilic Campylobacter, Listeria spp. and Escherichia coli were identified in both animal and environmental samples, while Salmonella spp. and Yersinia enterocolitica were not found. Shedding of Campylobacter via feces deems to play an important role with regard to the distribution of this pathogen in sheep herds. For Listeria, a high contamination rate was found in the environment, which may play a role for this agent. Finally, the species identification of Campylobacter differs depending on the techniques: conventional techniques and PCR techniques revealed different results.