Differential infection properties of three inducible prophages from an epidemic strain of Pseudomonas aeruginosa

James, C; Fothergill, J; Kalwij, H; Hall, A; Cottell, J; Brockhurst, M; Winstanley, C

Abstract

Background: Pseudomonas aeruginosa is the most common bacterial pathogen infecting the lungs of patients with
cystic fibrosis (CF). The Liverpool Epidemic Strain (LES) is transmissible, capable of superseding other P. aeruginosa
populations and is associated with increased morbidity. Previously, multiple inducible prophages have been found
to coexist in the LES chromosome and to constitute a major component of the accessory genome not found in
other sequenced P. aerugionosa strains. LES phages confer a competitive advantage in a rat model of chronic
lung infection and may, therefore underpin LES prevalence. Here the infective properties of three LES phages
were characterised.
Results: This study focuses on three of the five active prophages (LESφ2, LESφ3 and LESφ4) that are members of
the Siphoviridae. All were induced from LESB58 by norfloxacin. Lytic production of LESφ2 was considerably higher
than that of LESφ3 and LESφ4. Each phage was capable of both lytic and lysogenic infection of the susceptible
P. aeruginosa host, PAO1, producing phage-specific plaque morphologies. In the PAO1 host background, the LESφ2
prophage conferred immunity against LESφ3 infection and reduced susceptibility to LESφ4 infection. Each
prophage was less stable in the PAO1 chromosome with substantially higher rates of spontaneous phage
production than when residing in the native LESB58 host. We show that LES phages are capable of horizontal gene
transfer by infecting P. aeruginosa strains from different sources and that type IV pili are required for infection by all
three phages.
Conclusions: Multiple inducible prophages with diverse infection properties have been maintained in the LES
genome. Our data suggest that LESφ2 is more sensitive to induction into the lytic cycle or has a more efficient
replicative cycle than the other LES phages.

Citation

James, C., Fothergill, J., Kalwij, H., Hall, A., Cottell, J., Brockhurst, M., & Winstanley, C. (2012). Differential infection properties of three inducible prophages from an epidemic strain of Pseudomonas aeruginosa. BMC Microbiology, 12(216), 1-10. https://doi.org/10.1186/1471-2180-12-216

• Journal Article Type: Article
• Publication Date: Jan 1, 2012
• Deposit Date: Mar 19, 2013
• Publicly Available Date: Mar 19, 2013
• Journal: BMC Microbiology
• Publisher: Springer Verlag
• Peer Reviewed: Peer Reviewed
• Volume: 12
• Issue: 216
• Pages: 1-10
• DOI: https://doi.org/10.1186/1471-2180-12-216
• Publisher URL: http://dx.doi.org/10.1186/1471-2180-12-216
• Related Public URLs: http://www.biomedcentral.com/bmcmicrobiol/