Table 4.
Mutations in Carbapenem Resistance Determinants and Efflux Pump Regulators
| Isolate | ST | MPM MIC | MPM Int | OprDa | MexR | NalC | NalD | MexZ | NfxB |
|---|---|---|---|---|---|---|---|---|---|
| 1 | Unknown | ≤0.25 | S | … | … | G71E | … | … | … |
| 2 | 281 | ≤0.25 | S | … | … | G71E, S209R | … | … | … |
| 3 | 17 | 16 | R | G76ARX | … | G71E, S209R | … | … | … |
| 4 | 260 | ≤0.25 | S | - | … | G71E, S209R | … | L138R | … |
| 5 | 111 | 4 | I | S100X | V126E | G71E | … | FSb | … |
| 6 | 111 | ≤0.25 | S | … | V126E | G71E | … | FSb | … |
| 7 | 260 | 1 | S | … | … | G71E | … | L138R | … |
| 8 | 281 | 0.5 | S | … | … | G71E, S209R | … | … | … |
| 9 | 446 | 8 | R | Y328X | V126E | G71E, A145V, S209R | … | … | … |
| 10 | 111 | 4 | I | S100X | V126E | G71E | … | Δ1-28c | … |
| 11 | 446 | 8 | R | Y328X | V126E | G71E, A145V, S209R | … | … | … |
| 12 | 111 | 4 | I | S100X | V126E | G71E | … | Δ1-28c | … |
| 13 | 111 | >16 | R | Y294X | V126E | G71E | … | FSb | … |
| 14 | 111 | 8 | R | S100X | V126E | G71E | … | Δ1-28c | … |
| 15 | 291 | 8 | R | FSd | … | G71E, S209R | … | … | … |
| 16 | 111 | 32 | R | Y294X | V126E | V115X | … | FSb | … |
| 17e | 27 | ND | S | … | V126E,V132A | G71E,S209R | … | L128M | … |
| 18e | 281 | ND | S | … | … | G71E,S209R | … | … | … |
| 19e | Unknown | ND | S | … | … | G71E | … | … | … |
| 20 | 446 | 8 | R | Y328X | V126E | G71E, A145V, S209R | … | … | … |
| 21 | 308 | 32 | R | FSf | V126E | G71E,D79E,S209R | L62P | NS | … |
| 22f | 132 | ND | S | … | … | G71E,S09R | … | … | … |
| 23 | 446 | 4 | I | Y328X | … | G71E, A145V, S209R | … | … | … |
All mutations are at the amino acid level unless otherwise specified.
Abbreviations: ∆, deletion; FS, frameshift; I, intermediate; Int, interpretation; MIC, minimum inhibitory concentration; MPM, meropenem; ND, not determined; NS, not sequenced; nt, nucleotide; R, resistant; S, susceptible; ST, sequence type; X, stop codon.
aOnly inactivating mutations (frameshifts, premature stop codons) are listed.
bDeletion of nt 38-47.
cDeletion of nt 1-84.
dDeletion of nt 62-74.
eMPM MICs not determined. Results shown are as reported by Oregon Health and Science University microbiology using VITEK2.
fInsertion of nt GG at position 484.