SEROLOGIC STUDIES OF ACTINOBACILLUS (HEMOPHILUS) PLEUROPNEUMONIAE STRAINS OF SEROTYPE-3 AND THEIR ANTIGENIC RELATIONSHIPS WITH OTHER A-PLEUROPNEUMONIAE SEROTYPES IN SWINE

  • 1 February 1988
    • journal article
    • research article
    • Vol. 49  (2) , 152-155
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.