[Characteristics of a Salmonella abortus ovis allergen]

Studies were carried out to obtain an allergen of Salmonella abortus ovis and establish its chemical composition and diagnostic value with guinea pigs and sheep infected with the same causative agent. It was found that the allergen produced contained a great amount of protein (75 per cent), an essentially low amount of sugars (11 per cent), and a negligible amount of total phosphorus (0.85 per cent). It was also established that the allergen did not induce the production of antibodies in rabbits following intravenous inoculation, and did not give any positive allergic reaction in normal guinea pigs after intradermal application. It was shown to have a high diagnostic value, detecting some 87 per cent of the infected guinea pigs and 85 per cent of the infected sheep. The allergen also showed high specificity - it did not induce a positive skin reaction in guinea pigs infected with Y. enterocoli type 9, E. coli, and S. cholerae suis.