Table I.
Y. pseudotuberculosis proliferation in various conditions
| Experiment #1a | |||||
| Media | Cell-associated | ||||
| Time point | Fold-increase | (± S.D.) | |||
| (hour) | Cfu/well | (± S.D.) | Cfu/well | (± S.D.) | |
| 13.0 × 104 | 968 | ||||
| 0 | 4.8 × 104 | 1.0 | 1064 | 1.0 | |
| 4.9 × 104 | 654 | ||||
| 7.4 × 105 | 5150 | ||||
| 4 | 6.6 × 105 | 8.6(1.1) | 4640 | 4.9 (0.3) | |
| 5.8 × 105 | 4320 | ||||
| 2.7 × 107 | 78000 | ||||
| 8 | 2.1 × 107 | 293 (54) | 60800 | 75 (10) | |
| 1.9 × 107 | 62800 | ||||
| Experiment #2b | |||||
| Cell-associated | |||||
| -Cytochalasin D | +Cytochalasin D | ||||
| Time point | Fold-increase | Fold-increase | |||
| (hour) | Cfu/well | (± S.D.) | Cfu/well | (± S.D.) | |
| 476 | 656 | ||||
| 0 | 503 | 1.0 | 768 | 1.0 | |
| 432 | 544 | ||||
| 13200 | 50400 | ||||
| 6 | 20000 | 39(9) | 52000 | 70 (14) | |
| 21200 | 35200 | ||||
Y. pseudotuberculosis was added to wells containing either tissue culture media alone or cultured RAW cells (MOI = 0.2). Shown is either the titer of the wells containing tissue culture media alone (media) or the number of bacteria recovered from wells containing RAW cells (cell-associated). Three independent wells for each condition were assayed and the fold-increases are indicated (± sample standard deviation). b. Similar infection as in Experiment #1 except that some cells were treated with 10 μg/ml cytochalasin D 30 minutes prior to the addition of the bacteria.