Development of an antigen-capture monoclonal antibody–based enzyme-linked immunosorbent assay and comparison with culture for detection of Salmonella enterica serovar Enteritidis in poultry hatchery environmental samples

Abstract

An antigen-capture enzyme-linked immunosorbent assay (ELISA) was developed for use as a presumptive screening test for detection of Salmonella enterica serovar Enteritidis and other group D Salmonella in poultry hatchery environments. A mixture of 2 monoclonal antibodies that recognize different forms of the lipopolysaccharide O-antigen was used for specific detection of group D Salmonella. The performance of the ELISA was evaluated in comparison to standard Salmonella culture procedures. Culture for each sample included nonselective enrichment with buffered peptone water and primary selective enrichment and delayed secondary enrichment with both tetrathionate and Rappaport–Vassiliadis broths. One thousand fifty-seven samples were collected from poultry hatcheries over a 5-year period (received in 85 submissions), and S. Enteritidis was recovered from 106 (10%) of them. The diagnostic sensitivity and specificity of the ELISA relative to culture were 97.2% and 99.6%, respectively, on a sample basis and were both 100% on a submission basis. Delayed secondary enrichment increased the number of S. Enteritidis culture and ELISA-positive samples as compared to nonselective enrichment and primary selective enrichment by 25%. A significantly higher ( P < 0.05) number of S. Enteritidis culture- and ELISA-positive results were obtained from Rappaport–Vassiliadis broth than from tetrathionate broth or buffered peptone water cultures. The results indicate that this ELISA procedure may be useful for screening poultry hatchery environmental samples for the presence of S. Enteritidis.