Effect of type A Pasteurella multocida fractions on bovine polymorphonuclear leukocyte functions

Publisher Website
Google Scholar
Abstract
The effect of various P. multocida fractions on bovine polymorphonuclear leukocyte (PMN) functions was examined in vitro by using 2 encapsulated strains, P-2383 and P-1062 (both are Carter capsular type A and of bovine origin). The ability of PMN to ingest Staphylococcus aureus and iodinate protein was significantly inhibited in the presence of live cells, heat-killed whole cells or saline-extracted capsules, but not in the presence of the decapsulated heat-killed cells. None of the fractions of the 2 strains inhibited nitroblue tetrazolium reduction by PMN. The saline extract did not inhibit the binding of I to protein by a reaction involving xanthine, xanthine oxidase and horseradish peroxidase. The PMN inhibitory factor was further characterized as a heat-stable capsular material of > 300,000 MW.