Hemagglutinating properties of Salmonella typhimurium strains isolated from avian sources

A total of 565 strains of Salmonella typhimurium and S. typhimurium var. copenhagen, isolated from avian species, were examined for their ability to cause hemagglutination of turkey erythrocytes. Results showed that 541 (95.7%) of the strains caused varying degrees of hemagglutination. The hemagglutinating principle was maintained in cultures stored at 5 degrees C. as formalized suspensions for as long as 6 months. It was destroyed by exposure to a temperature of 80 degrees C. for 1 minute or to absolute ethyl alcohol at 37 degrees C. for 24 hours. The hemagglutinating principle was best preserved in cultures by infrequent transfers, growth in liquid media, lyophilization or storage at low temperatures. Addition of d-mannose to bacteria-erythrocyte mixtures at a final concentration of 0.5% completely inhibited the hemagglutinating activity of the cultures. A concentration of 1% d-mannose added to crystal-violet-stained antigen preparations of S. typhimurium eliminated entirely the hemagglutinating effect of positive cultures and did not interfere with regular agglutination reactions. The hemagglutinating activity of S. typhimurium strains is apparently due to the presence of rigid appendage (fimgriae) on the surface of the bacterial cells. Results from these studies showed that fimbriated cultures are quite common among strains of S. typhimurium.