TABLE 1.
Contamination of eggs after challenge of hens with S. enterica serovar Enteritidis
| Straina | Route of infection | Dose (CFU) | No. of hens | % daily egg production | No. of eggs cultured | % total eggs positive for SE | % of eggs positive on day 1 postchallenge |
|---|---|---|---|---|---|---|---|
| Wild type SE6 | Oral | 6 × 108 | 40 | 72.5 | 313 | 1.3 | 4.3 |
| Intravenous | 5 × 107 | 21 | 47.8 | 211 | 0.5 | 8.0 | |
| Subcutaneous | 1 × 108 | 12 | 75.0 | 189 | 0.5 | 0 | |
| SE-HCD1 | Subcutaneous | 1 × 108 | 20 | 62.1 | 284 | 0.7 | 0 |
| SE-HCD2 | Oral | 2 × 108 | 12 | 79.2 | 209 | 0 | 0 |
| Intravenous | 1 × 108 | 9 | 9.5 | 18 | 22.0 | 67.0 | |
| Subcutaneous | 1 × 108 | 10 | 65.2 | 256 | 3.5 | 100.0 |
a
SE-HCD1 was prepared for challenge when cell density was 3.2 and the number of LU was 197,000. SE-HCD2 was prepared for challenge when cell density was 2.2 × 109 and the number of LU was 121,000.