Evaluation of the immune response to salmonella enteritidis infection and vaccination using immunoblotting and micro titer serum plate agglutination test

Abstract EN

This experiment was conducted to study the immune response of chickens to S.

enteritidis infection or different vaccines either by micro titer serum plate agglutination test or by immunoblot test.

Different groups were included: chickens vaccinated by live S.

enteritidis vaccine (s / c), chickens vaccinated by locally prepared or commercial S.

enteritidis bacterins intramuscularly (i.m), and chickens infected orally or intramuscularly by a pathogenic strain of S.

enteritidis.

Also, the effect of antibiotic treatment on the serological response in live vaccine or infection groups was studied.

Agglutination test could detect 100 % positive reactors in the first week post vaccination and challenge.

The results revealed that the highest serum micro plate agglutination titer was Log 10 3.8 obtained by locally prepared bacterin and also obtained by intramuscular infection with pathogenic S.

enteritidis.

Immunoblotting could detect reacting sera only in the second week post vaccination or infection.

Antibiotic (sulphatrimethoprime) treatment decreased the number of reacting bands in the immunoblot by 1-3 bands less than those infected and not treated with antibiotics.

Intramuscularly infected chicks showed 1-2 bands more than orally infected chicks.

Live pathogenic bacteria injected i.m.

produced higher geometric mean titers and more bands in the immunoblot than the bacterin prepared from the same strain and injected via the same route.