TYPING OF HEAT-STABLE SOLUBLE HAEMOPHILUS-PARASUIS ANTIGEN BY MEANS OF AGARGEL PRECIPITATION AND THE DOT-BLOT PROCEDURE

According to MOROZUMI's and NICOLET's (1986) investigations, a serological classification procedure for H. parasuis and to a certain extent, for H. parasuis-like strains was proposed on the basis of heat-stable cell antigens in the immunodiffusion test. It was possible to classify 72.8 % of the investigated strains serologically using this procedure. 7 of 12 serotypes were described for the first time. 60.1 % of the classified strains belonged to the already known serotypes SV 1 to SV 5, whereas the new serotypes SV Jena 6 to SV Jena 12 amounted to only 12.7 % of the field isolates. The serotypes SV Jena 7 to 9 are represented by H. parasuis-like strains. Unencapsulated strains and isolates of serotype SV 5 dominate in animals with Glasser's disease. The serotypes SV 1, SV 5, SV Jena 6 and SV Jena 10 proved to be highly virulent in SPF pigs, SV 2 and SV 4 were of medium virulence. The other serotypes were non-virulent. The high specificity in AGPT was not reproducible in the more sensitive dot-blot procedure. This must be taken into account, if the dot-blot is to be used for the classification of serotypes of H. parasuis. The results point to a participation of non-immunogenic polysaccharides in the detection reaction.