Table 4.
Characterization of the MexEF-OprN overproducersa
| Strain | MIC (μg/ml) |
Genotype (SNP) | Alteration(s) in regulators of MexEF-OprNb |
mRNA levels for indicated gene |
||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| CIP | LVX | GEN | TOB | AMK | APR | FEP | TIC | CAZ | ATM | IMP | MEM | MexS | MexT | MvaT | mexE | mexT | mexB | mexY | ||
| Reference strains | ||||||||||||||||||||
| PAO1-UW | 0.12 | 0.5 | 4 | 1 | 8 | 16 | 2 | 16 | 2 | 4 | 1 | 0.5 | ND | ‡d | ‡ | ‡ | 1 | 1 | 1 | 1 |
| PAO7H | 2 | 8 | 4 | 0.5 | 4 | 16 | 2 | 8 | 2 | 1 | 4 | 2 | 0002 | ‡ | *e | ‡ | 1,075 | 1 | 0.5 | 2.1 |
| Clinical strains | ||||||||||||||||||||
| 40.1 | 0.5 | 2 | 4 | 1 | 4 | 16 | 1 | 8 | 1 | 2 | 4 | 1 | 239A | E54G, G78S, †c | * | ‡ | 446 | 0.4 | 0.01 | 1 |
| 93.1 | 1 | 4 | 2 | 0.5 | 4 | 8 | 8 | 64 | 32 | 16 | 4 | 2 | 2812 | A75V, † | * | ‡ | 1,081 | 0.4 | 0.5 | 0.1 |
| 3936 | 2 | 4 | 2 | 0.5 | 2 | 8 | 0.5 | 4 | 0.5 | 1 | 4 | 0.5 | 859A | † | * | ‡ | 1,760 | 0.3 | 0.4 | 0.5 |
| 3963 | 1 | 2 | 4 | 1 | 2 | 16 | 1 | 8 | 1 | ≤2 | 4 | 0.5 | E882 | † | * | ‡ | 324 | 0.2 | 0.4 | 0.6 |
| 3974 | 1 | 4 | 4 | 1 | 8 | 16 | 8 | 64 | 4 | 16 | 4 | 4 | 6992 | A75V, † | * | ‡ | 128 | 0.3 | 2.3 | 22 |
| 4076 | 2 | 4 | 0.5 | 0.12 | 1 | 8 | 4 | 32 | 16 | 16 | 8 | 2 | 882A | † | * | ‡ | 2,281 | 0.3 | 0.6 | 0.2 |
| 4088 | 2 | 4 | 2 | 0.5 | 2 | 8 | 1 | 8 | 1 | 1 | 8 | 0.25 | B421 | † | G257S, * | ‡ | 678 | 0.3 | 0.6 | 0.6 |
| 4099 | 0.5 | 1 | 2 | 0.25 | 1 | 4 | 1 | 8 | 0.5 | 2 | 4 | 0.5 | A671 | T152A, † | * | Δ1bp (230) | 1,035 | 0.2 | 0.5 | 0.5 |
| 4177 | 0.5 | 1 | 8 | 0.5 | 2 | 8 | 4 | 64 | 16 | 32 | 16 | 2 | 802A | † | R166H, * | ‡ | 510 | 0.2 | 0.4 | 0.4 |
| 4198 | 2 | 4 | 1 | 0.25 | 1 | 8 | 1 | 8 | 1 | 1 | 4 | 1 | F42A | K17T, A175V, E181D, †, S289T, V308I, V318I | * | A115T | 1,013 | 0.5 | 0.4 | 0.6 |
a
CIP, ciprofloxacin; LVX, levofloxacin; GEN, gentamicin; TOB, tobramycin; AMK, amikacin; APR, apramycin; FEP, cefepime; TIC, ticarcillin; CAZ, ceftazidime; ATM, aztreonam; IMP, imipenem; MEM, meropenem. ND, not determined.
b
Amino acid positions refer to strain PAO1-UW (http:/www.pseudomonas.com).
c
†, the D249N substitution was considered nonsignificant because it was found also in PA14 and in seven environmental susceptible strains (data not shown).
d
‡, identical to the PAO1-UW sequence.
e
*, active mexT gene missing the 8-bp insert (34) found in PAO1-UW.