Current Microbiology

, Volume 55, Issue 5, pp 435–440

Replication of Legionella pneumophila in Floating Biofilms

  • Priscilla Declerck
  • Jonas Behets
  • Vincent van Hoef
  • Frans Ollevier
Article

Abstract

Biofilms are a major source of human pathogenic Legionella pneumophila in aquatic systems. In this study, we investigated the capacity of L. pneumophila to colonize floating biofilms and the impact of Acanthamoeba castellanii on the replication of biofilm-associated Legionella. Biofilms were grown in Petri dishes and consisted of Aeromonas hydrophila, Escherichia coli, Flavobacterium breve, and Pseudomonas aeruginosa. Six hours following inoculation, Legionella were detected in floating biofilms in mean concentrations of 1.4 × 104 cells/cm2 (real-time polymerase chain reaction) and 8.3 × 102 CFU/cm2 (culture). Two-way analysis of variance tests and fluorescent in situ hybridization clearly proved that increased biofilm-associated L. pneumophila concentrations were the result of intracellular replication in A. castellanii. Forty-eight hours after the introduction of A. castellanii in the Petri dishes, 90 ± 0.8% of the amoebae (infection rate) were completely filled with highly metabolic active L. pneumophila (mean infection intensity).

Keywords

Floating biofilms Legionella pneumophila Acanthamoeba castellanii Intracellular replication 

Copyright information

© Springer Science+Business Media, LLC 2007

Authors and Affiliations

  • Priscilla Declerck
    • 1
  • Jonas Behets
    • 1
  • Vincent van Hoef
    • 1
  • Frans Ollevier
    • 1
  1. 1.Laboratory of Aquatic EcologyZoological Institute, Katholieke Universiteit LeuvenLeuvenBelgium

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