Prävalenz und Quantifizierung von Arcobacter spp. im Gastrointestinaltrakt von Masthähnchen am Geflügelschlachthof

Prevalence and quantification of Arcobacter spp. in the intestinal tract of broiler chicken at the slaughterhouse

Arcobacter spp. are frequently detected in foods of animal origin, particularly in meat products. However, the source of Arcobacter contamination of chicken meat products are under debate.
Different studies concerning the prevalence of Arcobacter spp. in the intestinal content of broiler chicken determined contradictory results. Therefore, in the present study four different parts of the intestines were examined at five significant processing steps during chicken slaughtering in an abattoir. In total, 157 intestinal tracts originating from 19 different broiler chicken flocks were investigated qualitatively and semiquantitatively by selective enrichment.
Further species verification was conducted applying mPCR and rpoB-sequencing. After the first two processing steps, Arcobacter spp. was only sporadically detected in the intestinal contents after bleeding (2/32) and not detected after scalding (0/32). After defeathering, Arcobacter spp. were detected in 62 % (18/29) of the intestinal tracts. The prevalences ranged between 28 % (8/29) in the duodenal, 21 % (6/29) in the jejunal, 3 % (1/29) in the caecal and 55 % (16/29) in the rectal contents with loads of = 24,000 MPN/g in the rectal contents.
Furthermore, Arcobacter spp. were detected in 88 % (7/8) of the rectal tissue samples. The prevalences and loads of Arcobacter spp. in the intestinal contents after evisceration are comparable to those after defeathering. The data determined in the present study indicate that detection of Arcobacter spp. in the intestinal contents of broiler chicken carcasses is highly probable after defeathering and after evisceration. Furthermore, the prevalences and loads with Arcobacter spp. in the duodenal and jejunal contents as well as in the rectal tissue samples suggest a possible reservoir of Arcobacter spp. inside the broiler chicken. Specific colonization trials might provide important data concerning the role of broiler chicken as reservoir for Arcobacter spp. In addition, the possibility of cross-contamination with Arcobacter spp. originating from the environment inside the slaughterhouse need to be considered. In the process of broiler chicken slaughter examined in this study, the defeathering step appears to be of importance concerning cross-contamination with Arcobacter spp. The mechanical pressure released on the carcasses during the defeathering process needs to be investigated in detail concerning a possible reflux of the intestinal contents towards the duodenum and jejunum. Additionally, epidemiological studies are necessary to identify the source of crosscontamination with Arcobacter spp. in the chicken slaughterhouse.
The potential pathogenicity of the species A. butzleri and A. cryaerophilus together with the high prevalences of these species in chicken meat and the possible transmission via consumption of contaminated chicken meat highlight the necessity to identify the source of cross-contamination with Arcobacter spp. and their transmission route into the chicken slaughterhouse.