Detection and screening of Salmonella enteritidis-infected chickens with recombinant flagellin

Screening and identification of Salmonella enteritidis in commercial poultr y flocks have assumed principal roles in preventing transmission of this pa thogen to humans from hen eggs. Serologic diagnosis of S, enteritidis infec tion in commercial flocks currently relies on laboratory-based tests for de tection of antibodies co the lipopolysaccharide, whole flagella, and bacter ia. We amplified a sequence from the g,m flagellin of S, enteritidis, follo wed by cloning, expression, and purification of the protein. The recombinan t protein was first characterized by western blot and subsequently evaluate d as enzyme-linked immunosorbent assay (ELISA) antigen for detection of S. enteritidis infection. A coral number of 49 positive sera and 40 negative s era were tested for ELISA validation. A cutoff value of 0.14 was shown to b e sufficient to discriminate the negative and positive sera. Results obtain ed by testing sera raised against different bacterial strains/serotypes fur ther confirmed that this recombinant flagellin-based ELISA was indeed speci fic for the detection of S, enteritidis. Both sensitivity and specificity o f the developed ELISA test were comparable with a commercially available te st, indicating that it is a highly promising and reliable diagnostic tool f or S, enteritidis infection.