Characterization of outer membrane protein-enriched extracts from Pasteurella multocida isolated from turkeys.

Outer membrane protein (OMP)-enriched extracts of avian strains of Pasteurella multocida were examined by use of sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Culture medium did not have a significant effect on the OMP profiles of strains of P multocida examined; however, in vivo propagation had an appreciable effect on the OMP profile composition of the reference strain P-1059. Such bacteria, expressed several additional OMP in the 27-kD, 48-kD, 56-kD, 60-kD, 80-kD, and 94-kD molecular mass regions. These OMP were not detected in the electrophorogram of strain P-1059 grown in vitro. The OMP profiles of reference strains of the 16 serotypes of P multocida did not identify any serotype-specific protein markers. Field strains of serotype A:3 had variation in OMP profiles and did not express OMP that all were identical to that expressed by the reference strain P-1059. The live attenuated CU and M9 bacterial vaccine strains expressed strain-specific OMP markers of 48-kD and 45-kD molecular masses, respectively. These strain-specific OMP markers may be used to differentiate these strains from virulent field strains that are of the same serotype and isolated from turkeys that have succumbed to pasteurellosis as a result of vaccine-related reactions or breakdown in immunity.