TABLE 1.
Fluoroquinolone susceptibilities of S. pneumoniae mutants
| Strain | Mutation in QRDR of:
|
MIC (μg/ml) ofa:
|
||||||
|---|---|---|---|---|---|---|---|---|
| GyrA | ParC | CIP | NSFQ-105 | 1 | 2 | 3 | 4 | |
| 7785 | None | None | 1 | 0.06–0.125 | 0.12 | 0.5 | 4 | 2 |
| 2C6 | None | Ser-79→Tyr | 8 | 0.06–0.125 | 0.12 | 1 | 4 | 2 |
| 2C7 | None | Ser-79→Phe | 8 | 0.06–0.125 | 0.12 | 1 | 4 | 2 |
| 1S1 | Ser-81→Phe | None | 1–2 | 0.5 | 1 | 4 | >8 | >16 |
| 1S4 | Ser-81→Tyr | None | 1–2 | 0.5 | 0.5 | 2 | >8 | 16 |
| 3C4 | Ser-81→Tyr | Ser-79→Tyr | 64 | 1–2 | 2 | >4 | >8 | >16 |
| 2S1 | Ser-81→Phe | Ser-79→Tyr | 64 | 1–2 | 1–2 | >4 | >8 | >16 |
| 2S4 | Ser-81→Phe | Asp-83→Asn | 16 | 1 | 1–2 | >4 | >8 | >16 |
a
CIP, ciprofloxacin; NSFQ-105, 4-(4-aminophenylsulfonyl)-1-piperazinyl ciprofloxacin; 1 to 4, compounds 1 to 4, respectively.