Use of bacteriophages for control of escherichia coli O157

A method of reducing levels of E. coli O157 in a ruminant animal comprising:

• administering to a ruminant animal having E. coli O157 within its gastrointestinal tract at least one bacteriophage selected from the group consisting of:
• V4, V5, re-isolated V5, V7, V8, V11, and V14;
• and
• retaining said ruminant animal under conditions such that said bacteriophage infect and lyse said E. coli O157,
• thereby reducing levels of E. coli O157 within the gastrointestinal tract of said ruminant animal.

A method of selecting and isolating bacteriophages capable of lysing E. coli O157 comprising:

• administering to a ruminant animal having E. coli O157 within its gastrointestinal tract at least one bacteriophage selected from the group consisting of:
• V4, V5, V7, V8, V11, and V14;
• recovering gastrointestinal content from said ruminant animal;
• isolating bacteriophage from said gastrointestinal content;
• plating said isolated bacteriophage onto a suitable host;
• and
• purifying the resulting plaques.

A method of reducing levels of E. coli O157 in a matrix comprising:

• administering to the matrix containing E. coli O157 therein at least one bacteriophage selected from the group consisting of:
• V4, V5, re-isolated V5, V7, V8, V11 and V14;
• and
• retaining said matrix under conditions such that said bacteriophage infect and lyse said E. coli O157,
• thereby reducing levels of E. coli O157 within the matrix.

A method of preventing or reducing the severity of disease caused by E. coli O157 comprising:

• administering to an individual in need of such treatment a pharmaceutical composition comprising at least one bacteriophage selected from the group consisting of:
• V4, V5, re-isolated V5, V7, V8, V11 and V14;
• and
• retaining said individual under conditions such that said bacteriophage infect and lyse said E. coli O157,
• thereby reducing levels of E. coli O157 within the gastrointestinal tract of said individual.