Preparation and evaluation of Enteritidis antigen conjugated with nanogold for screening of poultry flocks.

AIM

The present work aimed to develop lateral flow immunochromatographic strip (ICS) test for detection of Enteritidis (SE) specific antibodies in chicken sera.

MATERIALS AND METHODS

A rapid lateral flow immunochromatographic test (LFIT) has been developed, in which SE Group D antigen labeled with the gold chloride molecules laid on the conjugate pad. protein A was used as capture antibody at the test line (T) of a nitrocellulose (NC) membrane and anti-SE antigen-specific rabbit antibodies were used as capture antibody at the control line (C) of the NC strip in the lateral flow layout device.

RESULTS

Using the developed LFIT, the minimal amount of SE-specific antibodies that can be detected in chicken serum sample was 1427 enzyme-linked immunosorbent assay (ELISA) unit/100 µl that was equal to 0.1 µg (Ab)/100 µl sample. 100 suspected serum samples collected from a poultry flock were tested with the prepared SE-LFIT kits and the locally prepared stained antigen, and the results were compared with those obtained from examination of these samples with Group D antibody ELISA kit as the gold standard test. The sensitivity, specificity, and accuracy of the prepared SE-LFIT antigen kits were 94.4%, 90%, and 94%, respectively, while those obtained with stained antigen were 88.8%, 90%, and 89%, respectively.

CONCLUSION

The developed test is a simple field rapid test of high sensitivity, specificity, and accuracy that can improve and facilitates rapid field surveillance of salmonellosis among chickens.