Bordetella bronchiseptica adherence to cilia is mediated by multiple adhesin factors and blocked by surfactant protein A

Infect Immun. 2005 Jun;73(6):3618-26. doi: 10.1128/IAI.73.6.3618-3626.2005.

Abstract

In the virulent state (Bvg+), Bordetella bronchiseptica expresses adhesins and toxins that mediate adherence to the upper airway epithelium, an essential early step in pathogenesis. In this study, we used a rabbit tracheal epithelial cell binding assay to test how specific host or pathogen factors contribute to ciliary binding. The host antimicrobial agent surfactant protein A (SP-A) effectively reduced ciliary binding by Bvg+ B. bronchiseptica. To evaluate the relative contributions of bacterial adhesins and toxins to ciliary binding, we used mutant strains of B. bronchiseptica in the binding assay. When compared to Bvg+ or Bvg- phase-locked B. bronchiseptica strains, single-knockout strains lacking one of the known adhesins (filamentous hemagglutinin, pertactin, or fimbriae) displayed an intermediate ciliary binding capacity throughout the coincubation. A B. bronchiseptica strain deficient in adenylate cyclase-hemolysin toxin also displayed an intermediate level of adherence between Bvg+ and Bvg- strains and had the lowest ciliary affinity of any of the Bvg+ phase strains tested. A B. bronchiseptica strain that was missing dermonecrotic toxin also displayed intermediate binding; however, this strain displayed ciliary binding significantly higher than most of the adhesin knockouts tested. Taken together, these findings suggest that virulent-state B. bronchiseptica expresses multiple adhesins with overlapping contributions to ciliary adhesion and that host production of SP-A can provide innate immunity by blocking bacterial adherence to the ciliated epithelium.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adhesins, Bacterial / physiology*
  • Animals
  • Bacterial Adhesion*
  • Bordetella bronchiseptica / physiology*
  • Cilia / microbiology*
  • Hemagglutinins / physiology
  • Pulmonary Surfactant-Associated Protein A / pharmacology*
  • Rabbits

Substances

  • Adhesins, Bacterial
  • Hemagglutinins
  • Pulmonary Surfactant-Associated Protein A