Hemagglutination by Pasteurella multocida of porcine origin.

A total of 25 fresh isolates of Pasteurella multocida from pigs were tested for the ability to agglutinate erythrocytes of different origins. Of the 18 isolates from pigs with atrophic rhinitis (AR), 8 (44%) agglutinated human type O erythrocytes, whereas none of the 7 isolates from pigs without AR did so. Hemagglutination was mannose sensitive, and the activity was destroyed by heating and by trypsinization but was not affected by formaldehyde treatment or by homogenization of bacterial cells. The other 14 erythrocyte species tested, including human types A and B, were not agglutinated by P. multocida. The present study provides evidence that certain P. multocida isolates from pigs with AR possess a mannose-sensitive hemagglutinin.