Purpose: The purpose of this study was to isolate, purify, and characterize a wide host range-specific (WHR) bacteriophage as a new bio-recognition element.
Methods: WHR bacteriophages that were isolated from a poultry processing plant using dot and single plaque assays were purified through PEG precipitation, CsCl ultra-centrifugation, and dialysis. The selectivity of the WHR bacteriophages was investigated against 44 foodborne pathogens using dot assays. Morphological characteristics of the WHR bacteriophages were confirmed using a TEM. The stability of the WHR bacteriophages was investigated by incubating for 1 h under varying pH (3, 4, 5, 7, 9, 11, and 12) and temperature (4, 10, 22, 37, 50, and 60oC) conditions. Gel-electrophoresis was performed, after the extraction of the DNA from WHR bacteriophages, to determine the size of its DNA.
Results: The WHR bacteriophages were isolated from water used in poultry processing plants, and its final concentration was determined to be 5.81 × 1011 PFU/mL. Clear zones were found against six foodborne pathogens including two strains of Escherichia coli O157:H7, Bacillus cereus, Aeromonas hydrophila, Pseudomonas aeruginosa, and Salmonella Heidelberg. TEM images of the WHR bacteriophages confirmed that it had a head (131 ± 2.70 nm) and a tail (169 ± 8.51 nm). The optimum pH and temperature of the WHR bacteriophages were found to be in the ranges of 4.0-11.0 and 4-37oC, respectively. Gel-electrophoresis indicated that the WHR bacteriophage consisted of dsDNA with a genome size of 23-27 kb.
Significance: The WHR bacteriophages were successfully isolated and purified, and this study showed that the WHR bacteriophages had sufficient possibility to be used as a bio-recognition element for the development of the biosensor method.