TABLE 2.
Genes positively selected during aztreonam exposure
| Locus name | Common gene name | Predicted gene function | % isolates with nonsynonymous mutations |
dN/dS ratio (decimal) |
Significance of dN/dS relative to no exposure group (P value) | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| No exposure group (n = 12) | Low resistance group (n = 12) | Medium resistance group (n = 25) | High resistance group (n = 11) | All isolates exposed to aztreonam (n = 48) | No exposure group (n = 12) | Low resistance group (n = 12) | Medium resistance group (n = 25) | High resistance group (n = 11) | All isolates exposed to aztreonam (n = 48) | ||||
| PA4110 | ampC | β-Lactamase precursor | 0.00 | 0.00 | 28.00 | 63.64 | 29.17 | 0/0 (UNDa ) | 0/0 (UND) | 7/0 (UND) | 13/0 (UND) | 20/0 (UND) | 6.20 × 10−5 |
| ERW19588 | Hypothetical protein | 0.00 | 0.00 | 24.00 | 18.18 | 16.67 | 0/0 (UND) | 0/1 (0) | 6/0 (UND) | 2/0 (UND) | 8/1 (8) | 1.80 × 10−2 | |
| PA4418 | ftsI | Penicillin binding protein 3 | 8.33 | 16.67 | 48.00 | 72.73 | 45.83 | 1/0 (UND) | 2/2 (1) | 18/0 (UND) | 15/1 (15) | 35/3 (11.67) | 9.68 × 10−3 |
| PA3168 | gyrA | DNA gyrase subunit A | 8.33 | 50.00 | 32.00 | 54.55 | 41.67 | 1/0 (UND) | 9/1 (9) | 9/2 (4.5) | 12/1 (12) | 30/4 (7.5) | 1.98 × 10−2 |
| PA4569 | ispB | Octaprenyl diphosphate synthase | 0.00 | 16.67 | 4.00 | 36.36 | 14.58 | 0/0 (UND) | 2/0 (UND) | 1/0 (UND) | 4/0 (UND) | 7/0 (UND) | 6.78 × 10−3 |
| PA0425 | mexA | Multidrug resistance protein MexA | 0.00 | 16.67 | 16.00 | 45.45 | 22.92 | 0/0 (UND) | 4/0 (UND) | 4/0 (UND) | 6/0 (UND) | 14/0 (UND) | 5.02 × 10−4 |
| PA2420 | opdJ | Outer membrane porin OpdJ | 0.00 | 8.33 | 24.00 | 9.09 | 16.67 | 0/0 (UND) | 1/1 (1) | 7/0 (UND) | 1/0 (UND) | 9/1 (9) | 6.78 × 10−3 |
| PA0958 | oprD | Outer membrane porin OprD | 8.33 | 58.33 | 32.00 | 27.27 | 37.50 | 1/0 (UND) | 9/0 (UND) | 10/1 (10) | 3/0 (UND) | 22/1 (22) | 1.88 × 10−2 |
| PA0847 | Diguanylate cyclase | 0.00 | 8.33 | 24.00 | 0.00 | 14.58 | 0/0 (UND) | 1/0 (UND) | 9/0 (UND) | 0/1 (0) | 10/1 (10) | 3.24 × 10−2 | |
| PA1866 | Hypothetical protein | 0.00 | 8.33 | 28.00 | 9.09 | 18.75 | 0/1 (0) | 1/0 (UND) | 8/2 (4) | 2/1 (2) | 11/3 (3.67) | 3.82 × 10−2 | |
| PA2480 | Probable two-component sensor | 0.00 | 0.00 | 16.00 | 36.36 | 16.67 | 0/0 (UND) | 0/0 (UND) | 4/1 (4) | 4/0 (UND) | 8/1 (8) | 6.78 × 10−3 | |
| PA2557 | Probable AMP-binding enzyme | 0.00 | 8.33 | 20.00 | 36.36 | 20.83 | 0/0 (UND) | 1/0 (UND) | 7/0 (UND) | 4/0 (UND) | 12/0 (UND) | 9.79 × 10−4 | |
| PA4681 | Hypothetical protein | 0.00 | 0.00 | 24.00 | 18.18 | 16.67 | 0/0 (UND) | 0/0 (UND) | 7/0 (UND) | 2/0 (UND) | 9/0 (UND) | 3.59 × 10−3 | |
| PA1798 | parS | Two component sensor ParS | 0.00 | 8.33 | 24.00 | 27.27 | 20.83 | 0/1 (0) | 1/2 (0.5) | 7/0 (UND) | 3/0 (UND) | 11/2 (5.5) | 1.60 × 10−2 |
| PA2426 | pvdS | Sigma factor PvdS | 0.00 | 16.67 | 28.00 | 45.45 | 29.17 | 0/0 (UND) | 2/0 (UND) | 9/0 (UND) | 6/0 (UND) | 17/0 (UND) | 6.20 × 10−5 |
| PA4282 | sbcC | Probable exonuclease | 0.00 | 8.33 | 24.00 | 18.18 | 18.75 | 0/0 (UND) | 1/0 (UND) | 8/1 (8) | 2/0 (UND) | 11/1 (11) | 9.89 × 10−3 |
a
UND, undefined, due to an absence of synonymous mutations.