Project No. 2491
Primary Supervisor
Prof Jeremy Webb – University of Southampton
Co-Supervisor(s)
Dr Franklin Nobrega – University of Southampton
Dr Joe Parker – University of Southampton
Prof Saul Faust – National Institute for Health and Care Research (NIHR)
Dr Alasdair Munro – University of Southampton
Summary
An emerging and rapidly expanding area of research has arisen from the discovery that bacteriophage, which are specialised viruses of bacteria, can have both positive and negative impacts on human health and disease states.
This can occur directly by shaping the ecology or physiology of their bacterial host cells or biofilms during infection, by driving changes in the human microbiome, or it can occur indirectly by influencing human metabolism or immunity.
Pf4 is a filamentous bacteriophage, initially isolated and described by the primary supervisor (Webb et al., 2003, 2004), that contains a single-stranded DNA genome and that was shown to promote bacterial aggregation, biofilm formation and chronic infections (Rice et al., 2009). The phage has subsequently been shown to produce a liquid crystalline matrix surrounding its P. aeruginosa bacterial host cells that can sequester antibiotics (Secor et al., 2015), and more recently it has also been shown that wounds infected with P. aeruginosa strains positive for filamentous phage are delayed in wound healing and that Pf4 can modulate human immunity to infection (e.g. Bach et al., 2022, Sweere et al. 2019). The liquid crystal matrix formed by filamentous phage occurs via interactions between biofilm and host-disease-relevant biopolymers and the phage particles. These long, negatively charged, filamentous virions enhance the biofilm viscosity, conferring increased adhesion and promoting resistance to a range of antibiotics. Within the lung environment, filamentous phage assist in bacterial adhesion to lung mucus, further disseminating P. aeruginosa bacteria host across the lung environment and promoting chronic airway infections, which were particularly evident in Cystic Fibrosis (CF) patients.
The objectives of this PhD will be to: 1) Determine how Pf4 influences biofilm structure, metabolism and antibiotic tolerance of P. aeruginosa during infection, in this case within CF clinical P. aeruginosa isolates; 2) Demonstrate that targeted engineering of biofilm/bacteriophage biology can enhance antimicrobial sensitivity and treatment efficacy in CF clinical P. aeruginosa isolates; 3) By using direct, non-destructive and label free techniques for clinical biofilm evaluation (Smart objective 4, 2b/3), provide proof of concept for biofilm disruption through the control of phage-biofilm interactions directly within in ex-vivo clinical samples.
References:
Bach MS, de Vries CR, Khosravi A, Sweere JM, Popescu MC, Chen Q, Demirdjian S, Hargil A, Van Belleghem JD, Kaber G, Hajfathalian M, Burgener EB, Liu D, Tran QL, Dharmaraj T, Birukova M, Sunkari V, Balaji S, Ghosh N, Mathew-Steiner SS, El Masry MS, Keswani SG, Banaei N, Nedelec L, Sen CK, Chandra V, Secor PR, Suh GA, Bollyky PL. Filamentous bacteriophage delays healing of Pseudomonas-infected wounds. Cell Rep Med. 2022 Jun 21;3(6):100656.
Rice SA, Tan CH, Mikkelsen PJ, Kung V, Woo J, Tay M, Hauser A, McDougald D, Webb JS, Kjelleberg S. The biofilm life cycle and virulence of Pseudomonas aeruginosa are dependent on a filamentous prophage. ISME J. 2009 Mar;3(3):271-82.
Secor PR, Sweere JM, Michaels LA, Malkovskiy AV, Lazzareschi D, Katznelson E, Rajadas J, Birnbaum ME, Arrigoni A, Braun KR, Evanko SP, Stevens DA, Kaminsky W, Singh PK, Parks WC, Bollyky PL. Filamentous Bacteriophage Promote Biofilm Assembly and Function. Cell Host Microbe. 2015 Nov 11;18(5):549-59.
Sweere JM, Van Belleghem JD, Ishak H, Bach MS, Popescu M, Sunkari V, Kaber G, Manasherob R, Suh GA, Cao X, de Vries CR, Lam DN, Marshall PL, Birukova M, Katznelson E, Lazzareschi DV, Balaji S, Keswani SG, Hawn TR, Secor PR, Bollyky PL. Bacteriophage trigger antiviral immunity and prevent clearance of bacterial infection. Science. 2019 Mar 29;363(6434):eaat9691
Webb JS, Thompson LS, James S, Charlton T, Tolker-Nielsen T, Koch B, Givskov M, Kjelleberg S. Cell death in Pseudomonas aeruginosa biofilm development. J Bacteriol. 2003 Aug;185(15):4585-92.
Webb JS, Lau M, Kjelleberg S. Bacteriophage and phenotypic variation in Pseudomonas aeruginosa biofilm development. J Bacteriol. 2004 Dec;186(23):8066-73.