Table 2.
Mutations associated with resistance to amoxicillin in strains with a previously acquired resistance to enrofloxacin, kanamycin, or tetracycline
| Gene product | Gene | Mutation | Pop. frequency | Strains |
|---|---|---|---|---|
| Transcriptional regulator | acrR | L204R, Del C205 | 0.98–1 | E1/4, K2/4 T2/4 |
| B-lactamase | ampC | C35A (promoter) | 1 | E4/4, K3/4, T1/4 |
| C-11 T (promoter) | 1 | E4/4, K3/4, T1/4 | ||
| Ins T after C4379837 (promoter) | 1 | K1/4 | ||
| Ins T after A4379015 (promoter) | 1 | T1/4 | ||
| Citrate lyase | citF | G432A | 1 | E4/4, K3/4, T1/4 |
| Glutamate synthase subunit | gltD | A80A | 0.18 | T1/4 |
| L-glyceraldehyde 3-phosphate reductase | gpr | L180F | 1 | T2/4 |
| CPS-53 glucosyl transferase | gtrS | V351 V | 0.96 | K1/4 |
| Acetolactate synthase/acetohydroxybutanoate synthase subunit | ilvH | G52C | 0.60–1 | E2/4, K2/4, T1/4 |
| Branched chain amino acid/phenylalanine ABC transporter membrane subunit | livH | G239R | 0.18 | E1/4 |
| Intermembrane phospholipid transport system subunit | mlaF | Ins AIT between T38-A39 | 0.65–0.66 | T2/4 |
| Large conductance mechanosensitive channel | mscL | L45Q | 0.98 | K1/4 |
| Mismatch repair protein | mutL | W390 L | 0.11–0.2 | T2/4 |
| Transcriptional regulator | ompR | E88A | 1 | E4/4, K3/4, T1/4 |
| RNA polymerase subunit α | rpoA | C269S | 1 | E1/4, K1/4 |
| RNA polymerase subunit β | rpoB | E564A | 0.15 | T1/4 |
| Sigma 70 | rpoD | D445V | 1 | E4/4 |
| Alternative sigma factor σS | rpoS | E16Stop | 0.96–1 | K2/4, T1/4 |
| Del Q59-E330 | 0.91–1 | T2/4 | ||
| Potassium ion transporter | trkG | G159D | 1 | K1/4 |
Del = deletion, Ins = insertion, underlined letters and numbers indicate nucleotides and their genomic position. Population frequency indicates the mutational frequency in the sequenced population. Strains indicates the prevalence of a mutation within different replicates. E: population with previously acquired resistance to enrofloxacin, K: population with previously acquired resistance to kanamycin, T: population with previously acquired resistance to tetracycline. X/Y: X indicates number of replicates with particular mutation, Y indicates total number of replicates that were sequenced. Mutations associated with resistance in a wild-type background are shown in bold. Mutations associated with the previous resistance have been omitted from the table