TABLE 5.
Phage treatment of ayu infected with P. plecoglossicidaa
| Expt | Avg fish wt (g) | Phage treatment | No. of dead fish/no. tested | % Mortality | Mean time to death (days) | Reisolation of P. plecoglossicida from survivors (no. positive/ no. examined) |
|---|---|---|---|---|---|---|
| 1 | 10 | Yes (0 h) | 5/20 | 25 | 11.4 | 0/15 |
| Yes (0 h) | 4/20 | 20 | 11.5 | 0/16 | ||
| No | 14/20 | 70 | 9.8 | 1/6 | ||
| No | 12/20 | 60 | 10.0 | 2/8 | ||
| 2 | 2.4 | Yes (1 h) | 0/50 | 0 | NDb | |
| No | 39/50 | 78 | 11.3 | ND | ||
| Yes (24 h) | 5/40 | 13 | 8.8 | ND | ||
| No | 32/40 | 80 | 5.7 | ND |
a
Fish were challenged by oral administration of bacterium (PTH-9802)-impregnated pellets and immediately (0 h) or 1 or 24 h later received phage (mixture of PPpW-3 and PPpW-4)-impregnated pellets. Fish were cultivated at 20°C and observed for 2 weeks, and the kidneys of survivors were examined for the presence of P. plecoglossicida.
b
ND, not done.