TABLE 6.
MICs and DHFRs for selected strains
| Straina | Antifolate | Passageb (MIC [μg/ml]) | Identity, phenotype, and/or mutation(s)c of:
|
|
|---|---|---|---|---|
| Chromosomally encoded DHFR | Plasmid-encoded DHFR(s) | |||
| SA145 | BAL0030543 | 0 (0.5) | wt | wt S1 |
| 37 (>128) | wt | wt S1 | ||
| +10× −Abx (16) | wt | wt S1, I31M S1d | ||
| BAL0030544 | 0 (0.25) | wt | wt S1 | |
| 47 (>128) | wt | L28S S1 | ||
| +10× −Abx (>128) | ND | ND | ||
| BAL0030545 | 0 (0.25) | wt | wt S1 | |
| 50 (128) | wt | wt S1, I31M S1d | ||
| +10× −Abx (128) | ND | ND | ||
| VRS1 | BAL0030543 | 0 (0.5) | wt | wt S1 |
| 15 (>128) | wt | L28V I31M S1 | ||
| +10× −Abx (128) | ND | ND | ||
| BAL0030544 | 0 (0.25) | wt | wt S1 | |
| 20 (>128) | wt | L28V I31M S1 | ||
| +10× −Abx (>128) | ND | ND | ||
| BAL0030545 | 0 (1) | wt | wt S1 | |
| 25 (>128) | wt | L28V I31M S1 | ||
| +10× −Abx (>128) | ND | ND | ||
| CN051 | BAL0030543 | 0 (0.25) | T46N, F98Y, K160E | None |
| 50 (64) | L24I, T46N, F98Y, K160E | None | ||
| +10× −Abx (16) | ND | ND | ||
| BAL0030544 | 0 (0.125) | T46N, F98Y, K160E | None | |
| 38 (>128) | T46N, F98Y, K160E | None | ||
| +10× −Abx (4) | T46N, F98Y, K160E | None | ||
| BAL0030545 | 0 (0.5) | T46N, F98Y, K160E | None | |
| 50 (64) | T46N, F98Y, K160E | None | ||
| +10× −Abx (1) | T46N, F98Y, K160E | None | ||
| CN057 | BAL0030543 | 0 (8) | L20I, F98Y, H149R | None |
| 50 (128) | L20I, F98Y, H149R | None | ||
| +10× −Abx (128) | ND | ND | ||
| BAL0030544 | 0 (8) | L20I, F98Y, H149R | None | |
| 15 (>128) | L20I, F98Y, H149R | None | ||
| +10× −Abx (128) | ND | ND | ||
| BAL0030545 | 0 (8) | L20I, F98Y, H149R | None | |
| 23 (>128) | L20I, F98Y, H149R | None | ||
| +10× −Abx (128) | ND | ND | ||
| CN225 | BAL0030543 | 0 (0.25) | wt | wt S1 |
| 50 (128) | wt | wt S1 | ||
| +10× −Abx (8) | wt | wt S1 | ||
| BAL0030544 | 0 (0.25) | wt | wt S1 | |
| 38 (>128) | wt | wt S1 | ||
| +10× −Abx (2) | wt | wt S1 | ||
| BAL0030545 | 0 (0.25) | wt | wt S1 | |
| 36 (>128) | wt | wt S1 | ||
| +10× −Abx (2) | wt | wt S1 | ||
| CN345 | BAL0030543 | 0 (0.125) | wt | None |
| 50 (16) | wt | None | ||
| +10× −Abx (2) | wt | None | ||
| BAL0030544 | 0 (0.06) | wt | None | |
| 33 (>128) | wt | None | ||
| +10× −Abx (2) | wt | None | ||
| BAL0030545 | 0 (0.06) | wt | None | |
| 50 (4) | wt | None | ||
| +10× −Abx (2) | ND | ND | ||
a
Designations beginning with SA indicate S. aureus strains; designations beginning with CN indicate (coagulase-negative) S. epidermidis strains.
b
+10× −Abx, subsequent passage of the strain from the preceding passage 10 times in MHB without antibiotic.
c
wt, wild type; ND, not determined.
d
Due possibly to the presence of a multicopy plasmid.