Burkholderia cenocepacia strains isolated from cystic fibrosis patients are apparently more invasive and more virulent than rhizosphere strains

Luisa Pirone, Alessandra Bragonzi, Alessio Farcomeni, Moira Paroni, Cristina Auriche, Massimo Conese, Luigi Chiarini, Claudia Dalmastri, Annamaria Bevivino, Fiorentina Ascenzioni

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24 Citations (Scopus)


Given the widespread presence of Burkholderia cenocepacia in the rhizosphere it is important to determine whether rhizosphere strains are pathogenic for cystic fibrosis patients or not. Eighteen B. cenocepacia strains of rhizosphere and clinical origin were typed by multi-locus sequence typing (MLST) analysis and compared for their ability to invade pulmonary epithelial cells and their virulence in a mouse model of airway infection. Although there was great variability, clinical strains were the most invasive in vitro. Almost all the rhizosphere and two clinical strains were defined as non-invasive, six clinical strains as invasive, and two strains of both clinical and environmental origin as indeterminate. Exposure of murine airways to clinical strains caused higher acute mortality than that seen after challenge with rhizosphere strains. Furthermore, both clinical and environmental strains were able to persist in the lungs of infected mice, with no significant differences in bacterial loads and localization 14 days after challenge. DNA dot blot analyses of AHL synthase, porin and amidase genes, which play a role in B. cenocepacia virulence, showed that they were present in B. cenocepacia strains irrespective of their origin. Overall, our results suggest that rhizosphere strains do not differ from clinical strains in some pathogenic traits. © 2008 The Authors.
Original languageEnglish
Pages (from-to)2773 - 2784
Number of pages12
JournalEnvironmental Microbiology
Issue number10
Publication statusPublished - Oct 2008
Externally publishedYes


All Science Journal Classification (ASJC) codes

  • Environmental Science(all)
  • Microbiology
  • Applied Microbiology and Biotechnology

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