TABLE 3.
Mechanisms of resistance in H. influenzae strains for which quinolone MICs were increased
| Strain | MIC (μg/ml)
|
Mutation
|
||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Gemifloxacin | Ciprofloxacin | Levofloxacin | Sparfloxacin | Grepafloxacin | Trovafloxacin | ParC | ParE | GyrA | GyrB | |
| 1 | 0.03 | 0.5 | 0.5 | 0.25 | 0.25 | 1 | S133-A, N138-S | None | S84-L | None |
| 2 | 0.125 | 0.25 | 0.25 | 0.25 | 0.5 | 0.25 | None | S458-L | S84-F | None |
| 3 | 0.125 | 1 | 1 | 0.5 | 0.5 | 1 | S84-I | None | S84-L | None |
| 4 | 0.25 | 1 | 0.5 | 0.25 | 2 | 0.5 | D83-N | Extra Sa | S84-F, D88-N | Q468-R |
| 5 | 0.25 | 1 | 1 | 1 | 1 | 1 | E88-K | G405-S | S84-Y | None |
| 6 | 0.5 | 2 | 2 | 1 | 1 | 4 | S84-R | D420-N | S84-L, A117-E | None |
| 7 | 0.5 | 2 | 2 | 1 | 1 | 4 | S84-R | D420-N | S84-L, A117-E | None |
| 8 | 0.5 | 2 | 2 | 1 | 1 | 4 | S84-R | D420-N | S84-L, A117-E | None |
| 9 | 1 | 8 | 4 | 8 | 4 | 8 | S84-R, N138-S | S458-A, S474-N | S84-F, D88-Y | None |
a
In-frame insertion in parE leading to insertion of serine between the serine at position 458 and the threonine at position 459.