Keywords : Biocontrol
Coliphages Lytic; as a potential biological control agent against E. coli (O157:H7) in a mouse model.
European Journal of Molecular & Clinical Medicine,
2021, Volume 8, Issue 3, Pages 1306-1317
The aim of this study was to isolate and characterize the phage for use as a potential
biological control agent against Escherichia coli O157: H7. A standard strain of E coli O157:
H7 (NCTC 12900, China) was used to isolate the lytic phage from bovine faeces and raw
wastewater. The spot-assay test was used to check phage activity. Characterization of phage
isolates included phage resistance to acidity and alkalinity, electron microscopy and PCR
assay for stx1, stx2, and cI genes. Isolate phages were tested where a cocktail was
administered to treat mice that was given a single oral dose (108 CFU) of Escherichia coli
(O157: H7) (NTCC 12900). Three phages (P1, P3, P4) were successfully isolated from the
sewage samples as they showed strong lytical activity against E. coli O157: H7 (NCTC 12900).
The P1 and P4 phages had icosahedral head and a long, flexible, thin, inelastic tail with the
tail fibers while the P3 phage had a less rigid, long and relatively thick tail with the tail fibers.
All phages found are resistant to pH 4-9. The PCR results revealed the absence of genomic
coding for stx1, stx2, and cI in the isolated phages. All mice treated with the phage gave a
negative result for culture of Escherichia coli O157: H7.