title: Bacterial doubling time modulates the effects of opsonisation and available iron upon interactions between Staphylococcus aureus and human neutrophils.
abstract: Staphylococcus aureus was grown exponentially at two doubling times (DT), one related to in vivo (DT 60 min) and one typical of laboratory conditions (DT 24 min), and under iron-poor and iron-rich conditions. Relative to the fast-grown phenotypes, both slow-grown phenotypes exhibited low surface hydrophobicity and low protein A expression, induced poorly in non-opsonised and opsonised chemiluminescence, and survived well in whole blood killing. In particular, slow-grown, iron-poor cocci demonstrated enhanced survival in whole blood killing which correlated with significant reduction in their association with polymorphonuclear leukocytes, compared to the three other phenotypes; iron sufficiency increased the ability to stimulate polymorphonuclear leukocytes irrespective of opsonisation status. Staphylococcal DT may, by influencing surface hydrophobicity, modify interactions with immune system components.
authors.affiliation: Department of Pathology, University of British Columbia, Vancouver, Canada.
authors.forename: G
authors.initials: G
authors.lastname: Domingue
authors.forename: J W
authors.initials: JW
authors.lastname: Costerton
authors.forename: M R
authors.initials: MR
authors.lastname: Brown
mesh_terms: D001770:Blood Bactericidal Activity; D006801:Humans; D007501:Iron / Q000378:metabolism*; D008163:Luminescent Measurements; D009504:Neutrophils / Q000382:microbiology*; D009895:Opsonin Proteins; D010587:Phagocytosis; D013205:Staphylococcal Protein A / Q000032:analysis; D013211:Staphylococcus aureus / Q000254:growth & development*; D013499:Surface Properties
chemical_list: D009895:Opsonin Proteins; D013205:Staphylococcal Protein A; D007501:Iron