Abstract
The display of peptides on the capsid of bacteriophage has become very attractive for a variety of applications. A previously isolated T-even-type PP01 bacteriophage was used to detect its host cell, Escherichia coli O157:H7. The phage small outer capsid (SOC) protein was used as a platform to present a marker protein, the green fluorescent protein (GFP), on the phage capsid. GFP was introduced into the C- and N- terminal regions of SOC to produce recombinant phages, PP01-GFP/SOC and PP01-SOC/GFP, respectively. Fusion of GFP to SOC did not change the host range of PP01. On the contrary, binding affinity of the recombinant phages to the host cell increased. Adsorption of the GFP-labeled PP01 phages to the E. coli cell surface enabled visualization of cells under a fluorescence microscope. The coexistence of insensitive E. coli K-12 (W3110) cells did not influence the specificity and affinity of GFP-labeled PP01 adsorption on E. coli O157:H7. Ten min incubation with GFP-labeled PP01 phage at MOI=1000, 4°C, visualized E. coli O157:H7 cells under fluorescence microscopy. The GFP-labeled PP01 phage could be a rapid and sensitive tool for E. coli O157:H7 detection.
