Frontiers in Microbiology (Jun 2014)

Bdellovibrio bacteriovorus directly attacks Pseudomonas aeruginosa and Staphylococcus aureus Cystic fibrosis isolates

  • Valerio eIebba,
  • Valentina eTotino,
  • Floriana eSantangelo,
  • Antonella eGagliardi,
  • Luana eCiotoli,
  • Alessandra eVirga,
  • Cecilia eAmbrosi,
  • Monica ePompili,
  • Riccardo Valerio eDe Biase,
  • Laura eSelan,
  • Marco eArtini,
  • Fabrizio ePantanella,
  • Francesco eMura,
  • Claudio ePassariello,
  • Mauro eNicoletti,
  • Lucia eNencioni,
  • Maria eTrancassini,
  • Serena eQuattrucci,
  • Serena eSchippa

DOI
https://doi.org/10.3389/fmicb.2014.00280
Journal volume & issue
Vol. 5

Abstract

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Bdellovibrio bacteriovorus is a predator bacterial species found in the environment and within the human gut, able to attack Gram-negative prey. Cystic fibrosis (CF) is a genetic disease which usually presents lung colonization by Pseudomonas aeruginosa or Staphylococcus aureus biofilms. Here, we investigated the predatory behaviour of B. bacteriovorus against these two pathogenic species with: i) broth culture; ii) ‘static’ biofilms; iii) field emission scanning electron microscope (FESEM); iv) ‘flow’ biofilms; v) zymographic technique. We had the first evidence of B. bacteriovorus survival with a Gram-positive prey, revealing a direct cell-to-cell contact with S. aureus and a new ‘epibiotic’ foraging strategy imaged with FESEM. Mean attaching time of HD100 to S. aureus cells was 185s, while ‘static’ and ‘flow’ S. aureus biofilms were reduced by 74% (at 24h) and 46% (at 20h), respectively. Furthermore, zymograms showed a differential bacteriolytic activity exerted by the B. bacteriovorus lysates on P. aeruginosa and S. aureus. The dual foraging system against Gram-negative (periplasmic) and Gram-positive (epibiotic) prey could suggest the use of B. bacteriovorus as a ‘living antibiotic’ in CF, even if further studies are required to simulate its in vivo predatory behaviour.

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