Аgglutination test and passive hemagglutination test as immunological methods of antigenisisty assessment of vaccines against poultry salmonellosis

Abstract

Salmonellosis ranks first among acute intestinal infections with an established pathogen in Ukraine. Poultry products are the most frequent source of human salmonellosis is the highest in both the world and Ukraine. Therefore, Salmonella-specific prevention measures in most countries are an issue of great importance. The study's goal was to compare the levels of antibodies against Salmonella to the enteritidis, Typhimurium, and infantis monoantigens in the serum of poultry immunized with the experimental bivalent, the trivalent vaccine against salmonellosis using the Agglutination test (AT) and Passive Hemagglutination test (PHA). The research of two Salmonella inactivated emulsified vaccines – bivalent (S. enteritidis) and trivalent (S. enteritidis, S. typhimurium and S. infantis) was conducted on one of the poultry farms of the Lviv region. The birds were vaccinated two times in the 14th day's interval. The sera samples were taken on the 14, 21, and 28th days after the last shot. The antibody (agglutinin) levels were assessed in the AT and PHA. Both vaccines (bivalent and trivalent) inducted an intense immune response in birds' organisms. The average antibody titers were 1 : 512 –1 : 717 using the AT and 1 : 4096 – 1 : 5734 using the PHA. The highest antibody levels were detected for S. Enteritidis: 1 : 5734 for trivalent vaccine and 1 : 5120 for bivalent one using PHA. AT antibody levels were lower: 1 : 717 for the trivalent vaccine and 1 : 640 for the bivalent. The antibody levels to S. typhimurium were: 1 : 4915 for trivalent vaccine and 1 : 4710 for bivalent (PHA) and 1 : 640 for trivalent vaccine 1 : 589 for bivalent on (AT). The lowest antibody levels were detected in S. Infantis in both tests. An interesting fact of S. infantis agglutinins presence in serum samples from poultry vaccinated with the bivalent vaccine in both tests may be explained by cross-immunity formed by S. enteritidis – S. typhimurium vaccine.