TABLE 8.
Duration and number of E. coli O157:H7 in cattle after rectal swab inoculation: low-dose experimenta
| Animal |
E. coli O157:H7 CFU/swab or CFU/g of feces on postdose day:
|
||||||||
|---|---|---|---|---|---|---|---|---|---|
| 0 | 6 | 13 | 20 | 27 | 34 | 41 | 48 | 55 | |
| LR1 | 0 | 6.0 × 102 | 9.0 × 101 | 0 | 0 | 0 | 0 | 0 | 0 |
| LR2 | 0 | 1.5 × 103 | E+b | 1.2 × 102 | E+ | 0 | E+ | 0 | E+ |
| LR3 | 0 | 2.0 × 104 | 0 | 0 | 3.0 × 101 | E+ | E+ | 0 | 0 |
| LR4 | 0 | E+ | 1.2 × 102 | E+ | 0 | 0 | 0 | 0 | 0 |
| LR5 | 0 | 4.6 × 103 | 3.0 × 101 | E+ | E+ | 0 | 0 | E+ | 0 |
| LR6 | 0 | E+ | E+ | E+ | E+ | E+ | E+ | E+ | 0 |
| LR7 | 0 | 9.0 × 101 | 1.2 × 103 | E+ | 0 | 0 | 0 | E+ | 0 |
| LR8 | 0 | 2.1 × 102 | 6.0 × 101 | 0 | E+ | E+ | E+ | E+ | E+ |
| LR9 | 0 | 6.0 × 101 | E+ | E+ | 0 | 0 | 0 | 0 | E+ |
| LR10 | 0 | 4.2 × 103 | 6.0 × 101 | 0 | E+ | E+ | 0 | 0 | 0 |
| LR11 | 0 | E+ | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| LR12 | 0 | 5.1 × 104 | E+ | E+ | 6.0 × 101 | E+ | E+ | E+ | 0 |
| LR13 | 0 | 9.0 × 101 | 6.0 × 101 | E+ | 0 | 0 | |||
| LR14 | 0 | 1.3 × 104 | 2.1 × 102 | 9.0 × 102 | 3.0 × 102 | 1.5 × 102 | 1.5 × 102 | E+ | 0 |
| LR15 | 0 | 6.5 × 104 | 6.0 × 101 | E+ | 0 | 0 | 0 | 0 | 0 |
| LR16 | 0 | 2.0 × 104 | 7.2 × 102 | E+ | 0 | E+ | E+ | E+ | E+ |
a
Five-month-old Holstein steers received a single rectal dose of 2.0×107 CFU of E. coli O157:H7 ATCC 43894.
b
E+, sample was positive by enrichment culture technique but not by direct culture technique; this indicates that the number of CFU/g was ≤50.