INTRASTRAIN VARIATION OF LIPOPOLYSACCHARIDE OF PASTEURELLA-MULTOCIDA IN TURKEYS

Objective-To document intrastrain variation of lipopolysaccharide (LPS ) in Pasteurella multocida and correlate these changes with changes in determinants associated with virulence. Animals-25 broad-breasted whi te turkeys. Procedure-Phenotypic bacterial variants were identified by lectin affinity and were assayed for adherence to epithelial cells an d complement resistance in vitro. The LPS purified from these variants was subjected to polyacrylamide gel electrophoresis and lectin affini ty analysis, Turkeys were challenge exposed, then observed for 1 week. At first sign of disease, or at the end of the study, turkeys were eu thanatized, necropsied, and inspected for gross lesions. Results-The L PS variant designated as Ricinus communis agglutinin-positive had grea ter adherence to epithelial cells, complement resistance, and virulenc e in turkeys than did the variant designated as R communis agglutinin- negative. Conclusions-Intrastrain variation of LPS exists in P multoci da, and changes in LPS are correlated with changes in virulence.