TABLE 1.
Effect of ATR on the enteropathogenicity of V. parahaemolyticus ST550, as determined by the suckling mouse modela
| Treatment | Inoculum density (108 CFU/ml) | Incubation time (h) | Intestine/ body wt (10−3) | Bacteria recovered (log CFU/g of intestine) |
|---|---|---|---|---|
| Culture medium | 41.2 ± 4.2 | 0 | ||
| Nonadapted control | 1 | 3.0 | 48.3 ± 3.7 | 3.65 ± 0.04 |
| Single-phase adaptation | 1 | 3.0 | 51.7 ± 2.6 | 4.02 ± 0.04* |
| Two-phase adaptation | 1 | 3.0 | 52.8 ± 4.2* | 4.11 ± 0.04*+ |
| Nonadapted control | 0.25 | 4.5 | 52.2 ± 3.4 | 4.37 ± 0.60 |
| Single-phase adaptation | 0.25 | 4.5 | 60.9 ± 3.8* | 5.16 ± 0.05* |
| Two-phase adaptation | 0.25 | 4.5 | 63.7 ± 4.1* | 5.27 ± 0.05* |
| Nonadapted control | 0.1 | 6.0 | 62.9 ± 4.1 | 5.29 ± 0.08 |
| Single-phase adaptation | 0.1 | 6.0 | 75.2 ± 4.5* | 5.56 ± 0.06 |
| Two-phase adaptation | 0.1 | 6.0 | 80.5 ± 3.7*+ | 5.75 ± 0.04 |
a
The nonadapted or adapted bacterial culture was infected at several different dosages given intragastrically to suckling mice, and the mice were sacrificed at several different incubation times. The intestine/body weight ratio and the population of the pathogen in the intestine of each mouse were also determined. Each group consisted of six mice, and blank medium was used as a negative control. *, significant when the adapted group was compared with the nonadapted control group at P < 0.05. +, significant when the single-phase-adapted group was compared with the two-phase-adapted group at the same dosage level at P < 0.05.