EN
The sera against Haemophilus somnus antigens were obtained by immunization of hens, a rabbit, a goat and a bull; four different routes of immunization were used. In the immunoblotting the reactivity of the obtained sera with H. somnus as well as that of strains of Salmonella gallinarum-pullorum, S. enteritidis, S. typhimurium and S. dublin isolated from poultry in Poland was examined. Intensive cross-reactions of the tested sera with a number of Salmonella antigens were noted (especially that of S. enteritidis regarded as the most common in the poultry flocks in Poland). Special interest was aroused by the antigens of the examined Salmonella strains, which show intensive reactions (+++ to ++++) with the antisera used. These are: S. enteritidis of 18, 22-23, 45-47, 49, 51, 59, 61, 82-83 and 90 kD; S. typhimurium of 22-23, 51, 55-57, 85-86 and 90 kD; S. gallinarum-pullorum of 22-23, 49, 51, 59, 61, 84, 90 and over 100 kD; S. dublin of 16, 18, 20-21, 25, 36, and 59 kD. Intensive reactions with lipopolysaccharides of all Salmonella species were noted, which seems to be the result of strong immunogenicity of H. somnus lipooligosaccharide and its crossreactivity with endotoxins of other gram-negative bacteria species. The obtained results lead us to examine if vaccination poultry with H. somnus antigens could give them effective protection against the spreading of Salmonella infection, if it could become an alternative method of immunoprophylaxis to those already existing in the poultry production.