Comparative efficacy of different antigenic preparations from Pasteurella multocida for detection of antibodies by enzyme immuno assay

Abstract

In this study IHA, plate ELISA and DIA were employed to monitor antibody from ducks vaccinated with three different types of vaccine ( bacterin, bacterin with adjuvant and sonicate adjuvanated vaccine) prepared from P. multocida. Three different type of antigens viz., Crude capsular extract (CCE), Potassium thiocyanate extract ( KSCN) and sonicated antigen were used to coat NCM/ microtitre plate or for sensitization of SRBC. Forty ducklings of four week age were used for immunization. They were divided into four groups each group comprising of ten ducklings. Groups one, two and three were vaccinated with bacterin, bacterin with adjuvant and sonicate adjuvanated vaccine, respectively. Antibody was monitored upto 35th day post vaccination by IHA, Plate ELISA and DIA, employing CCE, KSCN and sonicated antigen. Group one ( vaccinated with bacterin) gave a higher mean titre value followed by IHA and plate ELISA, irrespective of the type of antigen employed, followed by group three ( birds vaccinated with sonicate adjuvanated vaccine) and group two ( birds vaccinated with bacterin with adjuvant ). Irrespective of the antigens employed in the tests, plate ELISA gave the highest sensitivity ( cent per cent) followed by IHA and DIA, whereas the highest specificity was observed by DIA, over IHA and plate ELISA. When the comparison was made between antigens a high mean titre value was obtained with sonicated antigen, followed by KSCN extract and CCE. Crude capsular extract antigen gave cent per

cent specificity by all the tests, while the other two antigens gave a low percentage of specificity. As the immunological test with highest specificity is the one preferred, CCE was shown to be superior over KSCN extract and sonicated antigen in IHA, plate ELISA and DIA for the detection of specific antibodies against P. multocida in ducks.