TABLE 1.
Susceptibility of strains to selected fluoroquinolones and mutations in the parC, parE, gyrA, and gyrB genes
| Strains | MIC (μg/ml)a of:
|
Amino acid substitutionb
|
|||||
|---|---|---|---|---|---|---|---|
| CIP | SPA | CLX | ParC | ParE | GyrA | GyrB | |
| S. pneumoniae R6, M22 | 0.5 | 0.25 | 0.125 | — | — | — | — |
| S. oralis NCTC 11427T | 2 | 0.5 | 0.125 | — | ND | — | ND |
| S. oralis ATCC 10557T | 2 | 0.5 | 0.125 | — | ND | — | ND |
| S. oralis 3180 | 128 | 16 | 2 | Ser-79→Phe | ND | Ser-81→Tyr | ND |
| S. oralis 3870 | 64 | 8 | 1 | Ser-79→Phe | ND | Ser-81→Phe | ND |
| S. mitis NCTC 12261T | 1 | 0.25 | 0.06 | — | — | — | — |
| S. mitis 14 | 8 | 0.5 | 0.125 | Ser-79→Ile | — | — | — |
| S. mitis 112 | 8 | 0.5 | 0.125 | — | Pro-424→Gln | — | — |
| S. mitis 197 | 8 | 0.5 | 0.125 | Ser-79→Phe | — | — | Ser-494→Thr |
| S. mitis 718 | 16 | 1 | 0.5 | Ser-79→Ile | — | — | — |
| S. mitis 720 | 8 | 1 | 0.5 | — | — | — | — |
| S. mitis 888 | 2 | 0.5 | 0.125 | — | ND | — | ND |
| R13180C | 2 | ND | ND | Ser-79→Phe | ND | ND | ND |
| R23429C/3180A | 64 | ND | ND | Ser-79→Tyr | ND | Ser-81→Tyr | ND |
| R23429C/3870A | 32 | ND | ND | Ser-79→Tyr | ND | Ser-81→Phe | ND |