title: Bdellovibrio bacteriovorus directly attacks Pseudomonas aeruginosa and Staphylococcus aureus Cystic fibrosis isolates.
abstract: 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 behavior of B. bacteriovorus against these two pathogenic species with: (1) broth culture; (2) "static" biofilms; (3) field emission scanning electron microscope (FESEM); (4) "flow" biofilms; (5) 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 185 s, while "static" and "flow" S. aureus biofilms were reduced by 74 (at 24 h) and 46% (at 20 h), 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 behavior.
authors.affiliation: Microbiology Section, Department of Public Health and Infectious Diseases, "Sapienza" University Rome, Italy.
authors.forename: Valerio
authors.initials: V
authors.lastname: Iebba
authors.affiliation: Microbiology Section, Department of Public Health and Infectious Diseases, "Sapienza" University Rome, Italy.
authors.forename: Valentina
authors.initials: V
authors.lastname: Totino
authors.affiliation: Microbiology Section, Department of Public Health and Infectious Diseases, "Sapienza" University Rome, Italy.
authors.forename: Floriana
authors.initials: F
authors.lastname: Santangelo
authors.affiliation: Microbiology Section, Department of Public Health and Infectious Diseases, "Sapienza" University Rome, Italy.
authors.forename: Antonella
authors.initials: A
authors.lastname: Gagliardi
authors.affiliation: Microbiology Section, Department of Public Health and Infectious Diseases, "Sapienza" University Rome, Italy.
authors.forename: Luana
authors.initials: L
authors.lastname: Ciotoli
authors.affiliation: Microbiology Section, Department of Public Health and Infectious Diseases, "Sapienza" University Rome, Italy.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Virga
authors.affiliation: Microbiology Section, Department of Public Health and Infectious Diseases, "Sapienza" University Rome, Italy.
authors.forename: Cecilia
authors.initials: C
authors.lastname: Ambrosi
authors.affiliation: Microbiology Section, Department of Public Health and Infectious Diseases, "Sapienza" University Rome, Italy.
authors.forename: Monica
authors.initials: M
authors.lastname: Pompili
authors.affiliation: Department of Pediatrics and Neuropsychiatry, "Sapienza" University Rome, Italy.
authors.forename: Riccardo V
authors.initials: RV
authors.lastname: De Biase
authors.affiliation: Microbiology Section, Department of Public Health and Infectious Diseases, "Sapienza" University Rome, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Selan
authors.affiliation: Microbiology Section, Department of Public Health and Infectious Diseases, "Sapienza" University Rome, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Artini
authors.affiliation: Microbiology Section, Department of Public Health and Infectious Diseases, "Sapienza" University Rome, Italy.
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Pantanella
authors.affiliation: Sapienza Nanoscience and Nanotecnology Laboratories, Department of Fundamental and Applied Sciences for Engineering, "Sapienza" University Rome, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Mura
authors.affiliation: Microbiology Section, Department of Public Health and Infectious Diseases, "Sapienza" University Rome, Italy.
authors.forename: Claudio
authors.initials: C
authors.lastname: Passariello
authors.affiliation: Section of Microbiology, Department of Biomedical Sciences, University G. D'Annunzio Chieti, Italy.
authors.forename: Mauro
authors.initials: M
authors.lastname: Nicoletti
authors.affiliation: Microbiology Section, Department of Public Health and Infectious Diseases, "Sapienza" University Rome, Italy.
authors.forename: Lucia
authors.initials: L
authors.lastname: Nencioni
authors.affiliation: Microbiology Section, Department of Public Health and Infectious Diseases, "Sapienza" University Rome, Italy.
authors.forename: Maria
authors.initials: M
authors.lastname: Trancassini
authors.affiliation: Department of Pediatrics and Neuropsychiatry, "Sapienza" University Rome, Italy.
authors.forename: Serena
authors.initials: S
authors.lastname: Quattrucci
authors.affiliation: Microbiology Section, Department of Public Health and Infectious Diseases, "Sapienza" University Rome, Italy.
authors.forename: Serena
authors.initials: S
authors.lastname: Schippa
keywords: Bdellovibrio bacteriovorus; Cystic fibrosis; FESEM; Pseudomonas aeruginosa; Staphylococcus aureus; biofilm; predation