Alexandria Hammond, United States of America
NYU School of Medicine MicrobiologyAuthor Of 1 Presentation
PNEUMOCOCCAL INTERACTIONS WITH MUCUS AND IMPLICATIONS FOR PATHOGENESIS (ID 344)
Abstract
Background
Pneumococcal colonization of the upper respiratory tract is a highly dynamic process involving bacteria binding to mucus, as well as bacterial cleavage of mucus components to evade mucociliary clearance. Increased binding of Spn to nasal glycoconjugates leads to entrapment in mucus and to more successful host elimination of Spn by mucociliary activity.
Methods
We used a solid-phase adherence assay with immobilized mucus of human and murine origin to screen for Spn surface factors and enzymes that modify host glycoconjugates to study Spn-mucus associations; strains with differential mucus binding were further tested in a murine model of colonization.
Results
Capsule (CPS)-, neuraminidase (NanA, NanB)-, and O-glycosidase (Eng)-deficient mutants showed increased mucus binding in vitro. The capsule- and neuraminidase-deficient mutants had a colonization defect in vivo, consistent with their role in mucus binding. In vitro, incubation with Spn removed sialic acid from bound mucus and this activity was diminished with the SpnDnanAnanB [MOU1] [AH2] [AH3] mutant strain. Pre-treatment of mucus with neuraminidase reduced bacterial binding, confirming the role of sialic acid removal in mucus evasion.
Conclusions
Our study highlights the importance of sialic acid during Spn colonization in vitro and in vivo, and identifies Spn factors and enzymes necessary for mucus evasion.
Presenter of 1 Presentation
PNEUMOCOCCAL INTERACTIONS WITH MUCUS AND IMPLICATIONS FOR PATHOGENESIS (ID 344)
Abstract
Background
Pneumococcal colonization of the upper respiratory tract is a highly dynamic process involving bacteria binding to mucus, as well as bacterial cleavage of mucus components to evade mucociliary clearance. Increased binding of Spn to nasal glycoconjugates leads to entrapment in mucus and to more successful host elimination of Spn by mucociliary activity.
Methods
We used a solid-phase adherence assay with immobilized mucus of human and murine origin to screen for Spn surface factors and enzymes that modify host glycoconjugates to study Spn-mucus associations; strains with differential mucus binding were further tested in a murine model of colonization.
Results
Capsule (CPS)-, neuraminidase (NanA, NanB)-, and O-glycosidase (Eng)-deficient mutants showed increased mucus binding in vitro. The capsule- and neuraminidase-deficient mutants had a colonization defect in vivo, consistent with their role in mucus binding. In vitro, incubation with Spn removed sialic acid from bound mucus and this activity was diminished with the SpnDnanAnanB [MOU1] [AH2] [AH3] mutant strain. Pre-treatment of mucus with neuraminidase reduced bacterial binding, confirming the role of sialic acid removal in mucus evasion.
Conclusions
Our study highlights the importance of sialic acid during Spn colonization in vitro and in vivo, and identifies Spn factors and enzymes necessary for mucus evasion.