Table 3. Fluoroquinolone MICs of 68 high-level resistant Streptococcus pneumoniae isolates and amino acid changes in their DNA topoisomerase IV and gyrase genes, Spain, 2006*.
No. isolates | Amino acid substitution |
Efflux phenotype† | ||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
parC
|
parE
|
gyrA
|
MIC, μg/mL |
|||||||||||
S79 | S80 | D83 | D435 | E474 | S81 | E85 | CIP | LVX | MXF | |||||
4 | F | – | – | – | – | F | – | 64 | 16–32 | 4 | CIP | |||
21 | F | – | – | – | – | F | – | 32–128 | 16–32 | 2–8 | None | |||
1 | F | – | – | – | – | L | – | 64 | 32 | 2 | None | |||
1 | F | – | – | – | – | V | – | 64 | 32 | 4 | CIP | |||
3 | F | – | – | – | – | Y | – | 64–128 | 16–32 | 4 | None | |||
1 | F | – | – | – | – | – | G | 32 | 16 | 4 | None | |||
2 | F | – | – | – | – | – | K | 32–64 | 16–32 | 2–4 | None | |||
1 | Y‡ | –‡ | –‡ | –‡ | –‡ | F‡ | –‡ | 64 | 32 | 4 | None | |||
8 | Y | – | – | – | – | F | – | 32–64 | 16–32 | 2–4 | None | |||
1 | Y | – | – | – | – | F | – | 64 | 32 | 4 | CIP, LVX | |||
1 | Y | – | – | – | – | Y | – | 64 | 32 | 4 | None | |||
1 | Y | – | – | – | – | – | K | 32 | 16 | 2 | None | |||
1 | – | P | – | – | – | F | – | 16 | 4 | 0.5 | None | |||
1 | – | – | H | – | – | F | – | 32 | 16 | 2 | CIP | |||
1 | – | – | Y | – | – | F | – | 32 | 16 | 2 | CIP | |||
2 | – | – | Y | – | – | F | – | 32 | 8–16 | 2–4 | None | |||
1 | – | – | N | – | – | – | K | 16 | 8 | 2 | None | |||
3 | – | – | – | N | – | F | – | 16 | 8 | 0.5–2 | None | |||
1 | –‡ | –‡ | –‡ | N‡ | –‡ | F‡ | –‡ | 16 | 4 | 0.5 | CIP | |||
1 | F | – | G | – | – | F | – | 64 | 32 | 4 | CIP, LVX | |||
2 | F | – | G | – | – | F | – | 32–64 | 32 | 4 | None | |||
1 | F | – | G | – | – | L | – | 64 | 64 | 16 | None | |||
1 | F | – | H | – | – | F | – | 64 | 32 | 4 | None | |||
2 | F | – | N | – | – | F | – | 32–64 | 16–32 | 4 | None | |||
2 | F | – | – | N | – | F | – | 64–128 | 32–128 | 4–32 | None | |||
1 | F | – | – | N | – | – | K | 16 | 32 | 4 | None | |||
1 | F | – | – | – | K | F | – | 64 | 32 | 4 | None | |||
1 | F | – | – | – | – | F | A | 64 | 16 | 4 | None | |||
1 | F | – | – | – | – | F | K | 32 | 32 | 4 | None |
*par, topoisomerase gene; gyr, gyrase gene; CIP, ciprofloxacin; LVX, levofloxacin; MXF, moxifloxacin. Only changes involved in resistance are shown. –, no change. Additional amino acid changes not involved in resistance were parC D83E (1), parC K137 N (24), parC N91D (2 with mosaic parC genes), parE I460V (47), and gyrA S114G (2 with mosaic gyrA genes). †An isolate was considered to have an efflux phenotype for the indicated fluoroquinolone when a >2-fold decrease in its MIC in the presence of reserpine was observed. ‡Indicates that the residue is located in a recombinant gene.