Establishment of an enzyme-linked immunosorbent assay with a coated deflagellated Salmonella enteritidis antigen for detection of a specific chicken antibody.

We attempted to establish an enzyme-linked immunosorbent assay (ELISA) for field monitoring/profiling purposes for Salmonella enteritidis (SE) infection of poultry flocks. Serotyping rabbit sera, commercially obtained, specific for Salmonella identification sera to O2, O4, O7, O8, S. Vi, S. Hm, and O9, showed negative ELISA (E)-values (< 0.2) on ELISA, except the O9 identification serum (E-value > 0.5). Similar negative E-value results were obtained for antisera to Echerichia coli (E. O antigen). Field serum samples originating from SE-isolated flocks yielded similar positive ratios on both ELISAs including the present coated deflagellated SE antigen and a commercially obtained flagellated SE antigen and that of rapid plate aggregation with a pullorum antigen (PD-RPA). About 100 days after the first monitoring, no SE isolation in the same flock was observed resulting in a carrier state of SE infection. Although both the monitoring results with commercially obtained ELISA and PD-RPA showed lower positive or negative ratios, the present ELISA showed a higher positive ratio than that of the first monitoring. The present ELISA is suggested to be a suitable method to do accurate profiling on the carrier state of infection.