Table 2.
Efficiency of plating for bacteriophages with O157+ and O157–E. coli strains.
| A. Comparison of phage titers on E. coil 43895Δper (O157–) a and 4783 (O157+) b | ||
|---|---|---|
| Phage and Bacteria Pairs c | Titer d (PFU/mL) | EOP e |
| Phage 12 900 Shy on E. coli 43895Δper | 1.82×1010 | |
| Phage 12 900 Shy on E. coli 4783 | 3.47×1010 | 0.52 |
| Phage 5947 Ace on E. coli 43895Δper | 4.0×107 | |
| Phage 5947 Ace on E. coli 4783 | 1.69×108 | 0.24 |
| B. Comparison of phage titers on E. coli 43895Δper (O157–) and 43 895 (O157+)f | ||
| Phage and Bacteria Pairs | Titer (PFU/mL) | EOP |
| Phage 12 900 Shy on E. coli 43895Δper | 1.25×1010 | |
| Phage 12 900 Shy on E. coli 43895 | 1.42×1010 | 0.88 |
| Phage 5947 Ace on E. coli 43895Δper | 7.30×107 | |
| Phage 5947 Ace on E. coli 43895 | 7.10×107 | 1.0 |
a
E. coil 43895Δper (O157–), perosamine deletion mutant that is negative for the O157 antigen.
b
E. coli 4783 (O157+), wild-type strain that is positive for the O157 antigen.
c
Phage and Bacteria Pairs, the designated phage was plated on the designated bacteria.
d
Titer, PFU/mL are means of triplicate determinations, all S.E. <0.05.
e
EOP, efficiency of plating.
f
43895 (O157+), E. coli 43895, isogenic parental strain positive for the O157 antigen.