Submitted to: Avian Diseases
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: June 2, 1998
Publication Date: N/A
Interpretive Summary: Although most commercial poultry breeding flocks are subjected to blood testing to detect antibodies to Salmonella pullorum, occasional outbreaks of pullorum disease are still reported. This has raised questions about whether the traditional methods for pullorum disease blood testing are still effective for detecting the S. pullorum strains currently prevalent in commercial poultry. Other recent studies have shown that many S. pullorum strains are recognized by antibodies generated against the flagella of other types of Salmonellae. The present study considered whether assays to detect antibodies to flagella could be applied for the detection of experimental S. pullorum infections. After hens were orally infected with S. pullorum, antibodies were detected in similar percentages of the birds by applying either traditional agglutination tests or flagellar enzyme immunoassays to blood samples. These antibodies to flagella, if also produced by naturally infected chickens, could provide the basis for an alternative method for detecting pullorum disease in poultry flocks.
Technical Abstract: Occasional Salmonella pullorum outbreaks still occur in commercial poultry flocks despite widespread serological testing, raising concerns about the efficacy of standard agglutination-based serological assays for detecting infections with current field strains. The recent observation that many S. pullorum strains are recognized by antibodies to certain Salmonella flagellar proteins suggests that similar antibodies might be elicited in infected birds. The present study assessed the capabilities of flagella- based enzyme immunoassays and several agglutination assays to detect antibodies in hens experimentally infected with recent S. pullorum isolates. Antibodies were detected in 33-41% of serum samples from orally inoculated hens using the various agglutination tests and in 29-44% of these samples using 2 flagella-based enzyme immunoassays. Antibodies to flagellar antigens, if also present in naturally infected chickens, could provide an alternative method for detecting S. pullorum infection in poultry flocks.