AUTHOR=Iebba Valerio , Totino Valentina , Santangelo Floriana , Gagliardi Antonella , Ciotoli Luana , Virga Alessandra , Ambrosi Cecilia , Pompili Monica , De Biase Riccardo V. , Selan Laura , Artini Marco , Pantanella Fabrizio , Mura Francesco , Passariello Claudio , Nicoletti Mauro , Nencioni Lucia , Trancassini Maria , Quattrucci Serena , Schippa Serena 

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

JOURNAL=Frontiers in Microbiology

VOLUME=5

YEAR=2014

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2014.00280

DOI=10.3389/fmicb.2014.00280

ISSN=1664-302X

ABSTRACT=<p><italic>Bdellovibrio bacteriovorus</italic> 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 <italic>Pseudomonas aeruginosa</italic> or <italic>Staphylococcus aureus</italic> biofilms. Here, we investigated the predatory behavior of <italic>B. bacteriovorus</italic> 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 <italic>B. bacteriovorus</italic> survival with a Gram-positive prey, revealing a direct cell-to-cell contact with <italic>S. aureus</italic> and a new “epibiotic” foraging strategy imaged with FESEM. Mean attaching time of HD100 to <italic>S. aureus</italic> cells was 185 s, while “static” and “flow” <italic>S. aureus</italic> biofilms were reduced by 74 (at 24 h) and 46% (at 20 h), respectively. Furthermore, zymograms showed a differential bacteriolytic activity exerted by the <italic>B. bacteriovorus</italic> lysates on <italic>P. aeruginosa</italic> and <italic>S. aureus</italic>. The dual foraging system against Gram-negative (periplasmic) and Gram-positive (epibiotic) prey could suggest the use of <italic>B. bacteriovorus</italic> as a “living antibiotic” in CF, even if further studies are required to simulate its <italic>in vivo</italic> predatory behavior.</p>