Abstract
Various kinds of treated cells were prepared from variants derived from serotype 1 strains of Haemophilus paragallinarum by enzymatic or physicochemic treatments. Hemagglutinating properties of the treated cells were investigated against freshly collected and glutaraldehyde-fixed chicken, human being (type O), or rabbit erythrocytes (RBC). At least 3 types of hemagglutinin showing different hemagglutination patterns, designated as hemagglutinins HA-L, HA-HL, and HA-HS, were defined from the results of their biologic properties. Heat-labile, trypsin-sensitive HA-L hemagglutinin agglutinated all RBC used, whereas trypsin-resistant heat-labile, HA-HL or heat-stable, HA-HS antigens agglutinated only fresh chicken or rabbit RBC except those from day-old chicks. Because of the presence of capsule surrounding bacterial cells, nontreated cells prepared from certain variant lacked the ability to agglutinate any RBC used; hyaluronidase-treatment rendered them agglutinate, and the hemagglutinin appeared by this treatment was HA-L hemagglutinin. After trypsin-or heat-treatment of HA-L hemagglutinin, hemagglutinins HA-HL or HA-HS appeared. Electron microscopic studies showed that the outer membrane of the treated cells adhered directly to the surface of RBC. The result suggests that the location of the 3 types of hemagglutinin HA-L, HA-HL, and HA-HS are in the outer membrane of bacterial cells, and indicates the necessity in use of proper hemagglutinin and RBC for experiment.
