The capsular polysaccharides of Pasteurella multocida serotypes B and E: Structural, genetic and serological comparisons.

Michael, Frank St; Cairns, Chantelle M; Fleming, Perry; Vinogradov, Evgeny V; Boyce, John D; Harper, Marina; Cox, Andrew D

We describe the structural characterization of the capsular polysaccharides (CPSs) of Pasteurella multocida serotypes B and E. CPS was isolated following organic solvent precipitation of the supernatant from flask grown cells. Structural analysis utilizing nuclear magnetic resonance spectroscopy enabled the determination of the CPS structures and revealed significant structural similarities between the two serotypes, but also provided an explanation for the serological distinction. This observation was extended by the development of polyclonal sera to the glycoconjugate of serotype B CPS that corroborated the structural likenesses and differences. Finally, identification of these structures enabled a more comprehensive interrogation of the genetic loci and prediction of roles for some of the encoded proteins in repeat unit biosynthesis.