Examining the presence of specific antibodies against Salmonella Enteritidis in vaccinated and unvaccinated poultry

Abstract

Introduction. The objective of our research was to point to the significance of serological diagnostic methods, that is, competitive immunoenzyme test - cELISA as well as the method of classical agglutination of O and H salmonella antigen, for specific antibodies against Salmonella enterica subspecies enterica serovar Enteritidis presence and titre detection in blood serum samples of bothvaccinated and unvaccinated poultry. Material and methods. In our work, we have used commercial competitive immunoenzyme test - cELISA and classical agglutination method with O and H antigens of Salmonella enterica subspecies enterica serovar Enteritidis. Comparative testing included 177 blood serum samples of poultry, out of which 137 was from unvaccinated and 40 from vaccinated individuals originating from majority of poutry farms. Results. In 74 blood serum samples, that is 54,01% out of the total of tested samples originating from unvaccinated flocks, by the use of cELISA test, there were found specific antibodies against S. Enteritidis, while by the method of classical agglutination specific antibodies against O antigen 1,9 and 12 were found in 58 samples, that is in 42,34%, and specific antibodies against H antigen g and m were found in 61 samples, what was 44,53% . In all the tested blood serum samples of vaccinated poultry, there was determined the presence of specific antibodies against S. Enteritidis, both by the use of competitive cELISA method and classical agglutination with somatic O and flagellar H antigens. By the statistical analysis of the results obtained by the method of classical agglutination and cELISA use of kappa test, there was found out a very good compliance (kappa=0,813). Conclusion. Based on the compared results of blood serum testing on the presence of specific antibodies against S. Enteritidis, it can be concluded that cELISA and classic agglutination with O and H antigen methods have a significant place in serological diagnostics of poultry samonelosis, because their application enables detection of the titre of specific antibodies against S. Enteritidis presence in the population of unvaccinated poultry sensitized with antigens of the mentioned causative agent, as well as in unvaccinated animals.

Uvod. Naša ispitivanja su imala za cilj da ukažu na opravdanost primene seroloških dijagnostičkih metoda, odnosno kompetitivnog imunoenzimskog testa - cELISA i metode klasične aglutinacije O i H antigena salmonela za utvrđivanje prisustva i titra specifičnih antitela protiv Salmonella enterica subspecies enterica serovar Enteritidis u uzorcima krvnog seruma vakcinisane i nevakcinisane živine. Materijal i metode. U radu su korišćeni komercjalni kompetitivni imunoenzimski test - cELISA i metoda klasične aglutinacije korišćenjem O i H antigena Salmonella enterica subspecies enterica serovar Enteritidis. Uporednim ispitivanjem obuhvaćeno je ukupno 177 uzoraka krvnog seruma živine poreklom od 137 nevakcinisanih i 40 vakcinisanih jedinki sa većeg broja živinarskih farmi. Rezultati. Kod 74 uzorka krvnog seruma, odnosno 54,01% od ukupnog broja ispitanih uzoraka seruma živine iz nevakcinisanih jata, primenom cELISA ustanovljena su specifična antitela protiv S. Enteritidis, dok su metodom klasične aglutinacje specifična antitela protiv O antigena 1,9 i 12 utvrđena kod 58 uzoraka, tj. kod 42,34% ispitanih uzoraka, a specifična antitela protiv H antigena g i m ustanovljena kod 61 uzorka, što iznosi 44,53% od ukupnog broja ispitanih uzoraka poreklom od nevakcinisanih jedinki. U svim ispitivanim uzorcima krvnih seruma vakcinisane živine utvrđeno je prisustvo specifičnih antitela protiv S. Enteritidis i to kako primenom kompetitivne cELISA metode tako i klasičnom aglutinacjom sa somatskim O i flagelarnim H antigenima. Statističkom analizom rezultata dobijenih metodom klasične aglutinacije i cELISA primenom kappa testa ustanovljeno je vrlo dobro slaganje (kappa=0,813). Zaključak. Na osnovu poređenja rezultata ispitivanja uzoraka krvnog seruma na prisustvo specifičnih antitela protiv S. Enteritidis, može se zaključiti da metode cELISA i klasična aglutinacija sa O i H antigenima zauzimaju značajno mesto u serološkoj dijagnostici salmoneloze živine jer se njihovom primenom omogućava otkrivanje prisustva i titra specifičnih antitela protiv S. Enteritidis u populaciji nevakcinisane živine senzibilisane antigenima navedenog uzročnika kao i kod vakcinisanih životinja.