title: Evidence of cytocidal effects of Pasteurella haemolytica on bovine peripheral blood mononuclear leukocytes.
abstract: Pasteurella haemolytica had a pronounced cytocidal effect on bovine mononuclear leukocytes. Mononuclear leukocytes separated from venous blood on Ficoll-diatrizoate and incubated with either P haemolytica or Escherichia coli showed a significantly greater percentage cell death than did cells incubated with Staphylococcus epidermidis or controls. Neither heat-killed nor x-irradiated P haemolytica caused a significant percentage cell death. The cytotoxic potential of P haemolytica was dose related in that cell death among mononuclear leukocytes increased as the ratio of bacteria-to-cells increased. Enriched monocyte cultures showed a higher and less variable rate of cell death than either enriched lymphocyte or mixed leukocyte cultures.
mesh_terms: D000818:Animals; D002417:Cattle / Q000382:microbiology*; D002470:Cell Survival; D002478:Cells, Cultured; D004926:Escherichia coli; D009000:Monocytes / Q000382:microbiology*; D010325:Pasteurella; D013210:Staphylococcus; D013997:Time Factors