title: Serologic studies of Actinobacillus (Haemophilus) pleuropneumoniae strains of serotype-3 and their antigenic relationships with other A pleuropneumoniae serotypes in swine.
abstract: Serotype-3 strains of Actinobacillus (Haemophilus) pleuropneumoniae possess epitopes shared with almost all other Actinobacillus serotypes. Common epitopes detected in particulate antigens were heat-labile and heat-stable and were of minor nature. Additional cross-reactive epitopes were detected in soluble and particulate antigens prepared from strains of serotypes 3, 6, and 8. Cross-reactions occurring between serotype-3 antigens and those of other serotypes were of 2 types: one associated mainly with 2-mercaptoethanol (2-ME)-sensitive IgM antibodies and the other associated mainly with 2-ME-resistant IgG antibodies. The cross-reactivity between serotypes 3, 6, and 8 was associated mainly with IgG antibodies, as shown by the results of 2-ME tube agglutination, 2-ME-indirect hemagglutination, and coagglutination tests. None of the tests was entirely satisfactory for serotyping serotype-3 isolates, mainly as a result of overlapping of type-specific antigenic determinants of serotypes 3, 6, and 8 in different combinations in the same strain. A combination of tests, using particulate and soluble antigens, may be necessary for typing of serotype-3 isolates.
mesh_terms: D000187:Actinobacillosis / Q000382:microbiology*; D000188:Actinobacillus / Q000145:classification / Q000276:immunology*; D000372:Agglutination Tests; D000818:Animals; D000907:Antibodies, Bacterial / Q000276:immunology; D000942:Antigens, Bacterial / Q000032:analysis* / Q000276:immunology; D003429:Cross Reactions; D000939:Epitopes / Q000032:analysis / Q000276:immunology; D006386:Hemagglutination Tests; D011001:Pleuropneumonia / Q000382:microbiology / Q000662:veterinary*; D012703:Serotyping; D013552:Swine; D013553:Swine Diseases / Q000382:microbiology*
chemical_list: D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D000939:Epitopes