TABLE 6.
Stability of rpoB mutations of sVISA strains
| Strain name | Colony sizea | Doubling time (min) | Vancomycin MIC at 48 h (mg/liter) |
rpoB mutation |
|
|---|---|---|---|---|---|
| Amino acid changeb | Codon sequence | ||||
| 17-6d (parent) | PC | 87.7 | 8 | S746F | TTT |
| 17-6d-L1 | LC | 44.4 | 3 | F746F | TTT |
| 17-6d-L2 | LC | 43.9 | 3 | F746F | TTT |
| 17-6d-L3 | LC | 64.8 | 3 | F746F | TTT |
| 21-4d (parent) | PC | 83.5 | 6 | H929T | TAT |
| 21-4d-L1 | LC | 41 | 3 | T929T | TAT |
| 21-4d-L2 | LC | 38.1 | 3 | T929H | TATGGT→CATGGGc |
| 21-4d-L3 | LC | 37.9 | 2 | T929H | TATGGT→CATGGGc |
| 21-4d-L4 | LC | 37.9 | 3 | T929H | TATGGT→CATGGGc |
| 21-4d-L5 | LC | 46.5 | 3 | H929T | TAT |
a
Observed at 20 h after streaking of the strain on BHI agar plate without vancomycin.
b
The rpoB gene sequence encompassing the single mutation was determined.
c
The sequences of 929th and 930th codons are shown.