1. Dispersing biofilms with engineered enzymatic bacteriophage
Doug Tischer

2. 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

3. 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

4. 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

5. 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

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

7. 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

8. 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.