TABLE 1.
Competitive colonization between respiratory mutants and wild-type E. coli strainsa
| Respiratory enzyme | Mutant(s) |
E. coli colonization (log10 CFU/g) by strain:
|
|||
|---|---|---|---|---|---|
| EDL933
|
MG1655
|
||||
| Day 1 | Day 9 | Day 1 | Day 9 | ||
| ATP synthetase | Δ(atpA-atpG) | 2.7 ± 0.1 | 5.6 ± 0.1 | 5.3 ± 0.5 | 5.9 ± 0.1 |
| Regulator of aerobic genes | ΔarcA | 4.7 ± 0.1 | 5.6 ± 0.2 | 3.0 ± 0.2 | 6.5 ± 0.3 |
| Regulator of anaerobic genes | Δfnr | 1.4 ± 0.2 | 5.6 ± 0.2 | 1.3 ± 0.1 | 6.8 ± 0.1 |
| Cytochrome bo oxidase | Δ(cyoA-cyoB) | 0.1 ± 0.1 | 0.4 ± 0.3 | 0.4 ± 0.1 | 0.8 ± 0.1 |
| Cytochrome bd oxidase | Δ(cydA-cydB) | 2.5 ± 0.1 | 5.2 ± 0.1 | 3.8 ± 0.2 | 5.0 ± 0.1 |
| Cytochrome bd oxidase (assembly) | Δ(cydD-cydC) | 2.4 ± 0.1 | 5.0 ± 0.2 | 3.3 ± 0.1 | 6.0 ± 0.2 |
| Nitrate reductase | ΔnarG | 0.3 ± 0.1 | 2.0 ± 0.1 | 0.4 ± 0.2 | 2.2 ± 0.1 |
| Nitrate reductase | ΔnarZ | 0.6 ± 0.1 | 0.1 ± 0.1 | 0.3 ± 0.1 | 0.1 ± 0.2 |
| Periplasmic nitrate reductase | Δ(napD-napA) | 0.4 ± 0.1 | 0.1 ± 0.1 | 0.2 ± 0.1 | 0.6 ± 0.1 |
| Nitrate reductases | ΔnarG, ΔnarZ | 0.9 ± 0.1 | 2.3 ± 0.1 | 0.1 ± 0.1 | 2.9 ± 0.2 |
| Nitrate reductases | ΔnarG, ΔnarZ, Δ(napD-napA) | 1.3 ± 0.1 | 3.1 ± 0.1 | 0.9 ± 0.1 | 3.8 ± 0.1 |
| Fumarate reductase | ΔfrdA | 0.8 ± 0.1 | 3.1 ± 0.2 | 0.1 ± 0.1 | 2.8 ± 0.2 |
a
Mice were fed 105 CFU each of a mutant and its wild-type parent. Mice were transferred to fresh cages every day, and feces no older than 24 h were assayed every other day for 15 days. At each time point, the log10 CFU/gram of feces for the mutant was subtracted from the log10 CFU/gram of feces for the wild type. The average ± standard error of the mean of day 1 and day 9 data from 6 mice is shown. Differences of at least 1 order of magnitude (10-fold) are in boldface type; all values shown in bold are statistically significant (P < 0.005; Student's t test).