TABLE 4.
Antibiotic susceptibility and resistance mechanisms of the heteroresistant parental isolates, their resistant subpopulations, and strains with OMC-induced resistance
| Strain | ST | MIC (mg/liter) for:c |
Mutation(s)d |
|||||||
|---|---|---|---|---|---|---|---|---|---|---|
| OMC plus CCCPa | OMC plus PAβN | OMC | TGC | RR1 | RR2 | RR3 | RR4 | S10 | ||
| EF16C361 | 179 | – | – | 0.5 | 0.25 | W | W | W | W | W |
| EF16C361-RSb | ≤0.03 | 0.5 | 4 | 2 | W | W | W | W | W | |
| EF16C361-IR | – | – | 8 | 8 | A1024C | T1088G/A1461G | A89G/C1265T/C1191T | W | W | |
| EF16C291 | 16 | – | – | 0.5 | 0.5 | W | W | W | W | W |
| EF16C291-RS | ≤0.03 | 0.5 | 4 | 2 | W | W | W | W | W | |
| EF16C291-IR1 | – | – | 8 | 4 | C1261T | G272A/A1461G | C1265T/C1191T | W | W | |
| EF16C291-IR2 | – | – | 16 | 4 | C988A/C1261T | G272A/G809A | C1265T/C1191T | W | W | |
| EF16C3 | 16 | – | – | 0.5 | 0.5 | W | W | W | W | W |
| EF16C3-RS | ≤0.03 | 0.5 | 2 | 2 | W | W | W | W | W | |
| EF16C3-IR1 | – | – | 16 | 16 | W | W/A1461G | C1265T/C1191T | W | W | |
| EF16C3-IR2 | – | – | 16 | 16 | W | W/A1461G | C1265T/C1191T | W | W | |
| EF16C28 | 179 | – | – | 0.5 | 0.25 | W | W | W | W | W |
| EF16C28-RS | ≤0.03 | 0.5 | 4 | 2 | W | W | W | W | W | |
| EF16C28-IR | – | – | 32 | 16 | W | T1041A/A1461G | C1265T/C1191T | W | W | |
| EF16C350 | 480 | – | – | 0.5 | 0.5 | W | W | W | W | W |
| EF16C350-RS | ≤0.03 | 0.5 | 4 | 2 | W | W | W | W | W | |
| EF16C350-IR | – | – | 16 | 4 | W | G878A | C1265T/C1191T | G811A/A1148G | W | |
| EF16C185 (EF16) | 16 | – | – | 0.5 | 0.5 | W | W | W | W | W |
| EF16C185-RS (EF16-O2) | ≤0.03 | 0.5 | 4 | 2 | W | W | W | W | W | |
| EF16C185-IR | – | – | 8 | 4 | C1261T/C743T | W | C860T/G1191A/G1265A/C1191T | W | W | |
| OG1RF | – | – | 0.125 | 0.125 | W | W | W | W | W | |
| OG1RF-IR1 | – | – | 32 | 32 | W | A1461G | C1265T/C1191T | C1416T | LYS57ARG | |
| OG1RF-IR2 | – | – | 32 | 32 | W | C914G/ATGA921-924TGAC/A1461 | C1265T/C1191T | W | HIS56TYR, LYS57ARG | |
a
CCCP, carbonyl cyanide m-chlorophenylhydrazone; PaβN, Phe-Arg-β-naphthylamide.
b
RS, OMC-resistant subpopulations; IR, isolates with OMC-induced resistance.
c
–, not determined.
d
In individual copies of 16S rRNA (RR1 to RR4) and the 30S ribosomal protein S10. W, wild-type.