A comparison of different enrichment media for the isolation of Salmonella dublin from livers, kidneys and muscles of Salmonella-positive veal calves.

Amongst a herd of 250, approximately 22 weeks old, Dutch Friesian veal calves, 84 were condemned on meat inspection because of typical pathology of salmonellosis, confirmed by isolation of Salmonella dublin from spleens. From the condemned animals 15 carcasses were randomly selected for further investigation. Their livers, kidneys and samples of their longissimus dorsi muscles were examined for Salmonella using Rappaport-Vassiliadis' and Muller-Kauffmann's enrichment media. In addition, livers were macroscopically scanned for necrotic foci. Signs of (multiple) miliary liver necrosis were not consistently related to isolation of Salmonella from the three tissues examined. Although all spleens had been found positive for Salmonella, from only 53% of the livers, 33% of the kidneys and 27% of the muscles could salmonellae be isolated by one or both enrichment procedures. The Rappaport-Vassiliadis enrichment medium was found to be slightly superior for the isolation of salmonellae. All Salmonella-isolates were serotyped as Salmonella dublin. Their antibiograms showed the expected resistance to chloramphenicol and tetracyclines but, surprisingly, sensitivity to ampicillin, kanamycin, neomycin and streptomycin.