Comparison of the Salmonella-Tek ELISA to culture methods for detection of Salmonella enteritidis in litter and cloacal swabs of poultry.

An enzyme-linked immunosorbent assay (ELISA), using the Salmonella-Tek ELISA test system, was compared with bacteriological isolation for detection of Salmonella enteritidis phage type 4 in litter and cloacal swabs of poultry. Before ELISA, samples were enriched in tetrathionate broth for 18-24 h or in tetrathionate broth (18-24 h), followed by M-broth/novobiocine (4-6 h). The bacteriological isolation procedure included incubation in buffered peptone water and inoculation on modified semisolid Rappaport-Vassiliadis. For detection of S. enteritidis in litter samples, ELISA was more sensitive than bacteriological examination. For cloacal swabs, both techniques were equally sensitive. The two enrichment procedures gave no significant differences in ELISA results. It was concluded that the Salmonella-Tek ELISA test might be a promising test for detection of Salmonella infected poultry flocks, providing that further studies are performed to determine the cut-off value for litter and cloacal swabs of commercial flocks.