Isolation and Characterization of bacteriophage from environmental soil samples

Bacteriophages are obligatory organisms which depend on host for survival and infect bacteria. Currently, the world is facing an antibiotic resistance problem which can be cured by phage therapy. The arm-race of coexistence between the bacteriophage and bacteria has developed different phage counter defence mechanisms in infecting the bacteria. This study approaches isolation and characterization of bacteriophages from two different geographical soil samples using E. coli K12 as a host strain followed by overlay method, host determination, and DNA analysis. There was no result of bacteriophage from the collected sample which determined numerous reasons such as absence of E. coli K12 specific phage, external environmental factors affecting the protocol and soil phage quality, composition of buffer etc. However, a positive control phage specific to E. coli K12 was enriched and resulted with diverse host range showing lysis activity against the unknown isolated soil bacteria with >1kbp genome size when analysed. Furthermore, no separation on the phage DNA was observed when treated with HindIII restriction enzyme. Therefore, the negative result can be studied further in the future by substituting the modified protocol from the traditional one, controlling the affective factors for better phage yield and the positive phage can be used in a phage therapy for the eradication of some antibiotic resistance bacteria.