Diagnosis of <em>Salmonella Enteritidis</em> Infection in Broiler Chickens Using Elisa

Abstract

The program for the eradication of Salmonella Enteritidis from chickens was based on bacteriological examination of breeding flocks. There is a great need for a specific and sensitive serological screening test. For that purpose, four different enzyme-linked immunosorbent assays (ELISAs) were developed. These included an indirect ELISA with Salmonella Enteritidis flagellin, an indirect ELISA with Salmonella Enteritidis lipopolysaccharide, a double-antibody sandwich blocking ELISA that uses monoclonal antibodies against Salmonella Enteritidis flagellin (GM-DAS blocking ELISA), and a double-antibody sandwich ELISA that uses monoclonal antibodies against Salmonella Enteritidis lipopolysaccharide. In this study, we compared the results of those ELISAs across sera from experimentally infected 1-day-old chickens and sera and eggs from experimentally infected laying hens. Experimental infections were induced with strains of Salmonella Enteritidis phage types 1 and 2 and Salmonella typhimurium. Sera were collected up to days 44 and 39 after infection from 1 day old chickens and laying hens, respectively. Only the GM-DAS blocking ELISA was able to discriminate between Salmonella Enteritidis infections and infections with the other serotypes. This ELISA had both sensitivity and specificity of 100% for all serum samples from experimentally infected chickens.