Sequence of primers for PCR amplification used throughout these studies.

<p>Sequence of primers for PCR amplification used throughout these studies.</p

Density (mean ± s. e.) of <i>P</i>. <i>caudatum</i> when co-cultured with matched MOI of <i>E</i>. <i>coli</i> O157:H7 EDL933 and cattle commensal <i>E</i>. <i>coli</i> (186) for three days at ambient laboratory temperature.

<p>Squares, <i>P</i>. <i>caudatum</i> with added <i>E</i>. <i>coli</i>; no marker, <i>P</i>. <i>caudatum</i> in trough water without added bacteria.</p

CFU (mean ± s. e.) of <i>E</i>. <i>coli</i> O157:H7 EDL933 and isogenic mutants inoculated at matched MOI when co-cultured with <i>T</i>. <i>pyriformis</i> (solid lines) and <i>P</i>. <i>caudatum</i> (dashed lines) at ambient laboratory temperature.

<p>(A) <i>E</i>. <i>coli</i> O157:H7 EDL933 (squares) and EDL933ΔStx 2a subunit A (triangles). (B) <i>E</i>. <i>coli</i> O157:H7 EDL933 (squares) and EDL933ΔStx 1 phage (diamonds). (C) <i>E</i>. <i>coli</i> O157:H7 EDL933 (squares) and EDL933ΔStx 2a phage (circles). (D) <i>E</i>. <i>coli</i> O157:H7 EDL933 (squares) and EDL933ΔStx 1 & Stx 2a phages (asterisks).</p

<i>E</i>. <i>coli</i> strains used in these studies.

<p><i>E</i>. <i>coli</i> strains used in these studies.</p

<i>P</i>. <i>caudatum</i> grazing of <i>E</i>. <i>coli</i> O157:H7 EDL933 and cattle commensal <i>E</i>. <i>coli</i> (186) over three days at ambient laboratory temperature.

<p>CFU (mean ± s. e.) for three grazing trials each containing a matched MOI of <i>E</i>. <i>coli</i> O157:H7 EDL933 (squares) and cattle commensal <i>E</i>. <i>coli</i> (triangles).</p