Dispersing biofilms with engineered enzymatic bacteriophage Doug Tischer

The Problem with Biofilms Increases resistant to antibiotics Pose a problem for cleaning medical devices, water pipe, food contamination from industrial devices etc EPS (Extracellular Polymeric Substance) Polysaccharides Proteins Nucleic Acids Lipids

The Idea Adhesin polymeric β-1,6-N-acetyl-D-glucosamine essential for bacterial adhesion to biofilm DspB degrades polymeric β -1,6-N-acetyl-D- glucosamine T3 gene 1.2 allows replication in F-plasmid- containing E. coli Figure taken from Lu, 2007

Construction T7wt T7DspB T7control Φ10 promotor expresses only during infection 10B is a capsid protein S-tag easily detected in western blot Figure taken from Lu, 2007

Results Crystal Violet Staining CFU Counts PFU Counts No replication (no T3 gene 1.2) Inoculation T3 gene 1.2 greatly enhances phage efficacy in F-plasmid containing E. coli DspB enhances plaque destruction Engineered phage is replicating PFU = Plaque forming unit Figure taken from Lu, 2007

Results cont. Treated Untreated 4.5 orders of magnitude drop = 99.997% drop in cell count Scanning Electron Microscope of cell plaques Significant disruption of plaques Figure taken from Lu, 2007

My thoughts Very practical application Liked Disliked Very practical application Showed phages can be engineered with several genes of interest without hindering replication Successful proof of principle Relatively simple construction No new behavioral tricks Only protein expression No use of premade parts

References Lu TK, Collins JJ (2007) PNAS 104:11197–11202 Mark McCormick and Robert Mierendorf. “S•Tag: A Multipurpose Fusion Peptide for Recombinant Proteins.” Novagen Inc.