TABLE 3.
Mutants selected as Kanr SCVs in FA-susceptible clinical isolates and then screened for FA resistance
| Strain and stock | Sourcea | Identified mutationb
|
Antibiotic MIC (μg/ml) of:
|
Doubling time (min)c | Auxotrophyd | ne | |||
|---|---|---|---|---|---|---|---|---|---|
| fusA (EF-G) | rplF (L6) | KAN | STR | FA | |||||
| IN476-IN494 | None | None | 2 | 6 | 0.047 | 24 | − | ||
| FusA-SCV | |||||||||
| AH421 | IN488 | Pro404Arg | None | 8 | 12 | 3 | 36 | − | |
| AH288 | IN476 | Gly617Asp | None | 16 | 32 | 6 | 53 | Hemin | 2 |
| AH294 | IN490 | Gly628Val | None | 16 | 8 | 2 | 40 | − | |
| AH287 | IN476 | Ala655Glu | None | 16 | 48 | 12 | 64 | Hemin | |
| AH291 | IN484 | Arg659His | None | 24 | 24 | 4 | 43 | − | |
| AH297 | IN492 | Ser660Pro | None | 24 | 2 | 53 | Hemin | ||
| AH296 | IN490 | Gly664Ala | None | 16 | 8 | 3 | 39 | − | |
| AH292 | IN484 | Gly666Val | None | 32 | 16 | 6 | 36 | − | |
| AH298 | IN494 | Gly666Val | None | 32 | 6 | 6 | 37 | − | |
| FusE | |||||||||
| AH422 | IN488 | None | +2 FS at nt 222 | 128 | 32 | 12 | 81 | Menadione | |
| AH290 | IN478 | None | Duplicate nt 202-293 | 256 | 64 | 8 | 200 | Menadione | |
| AH420 | IN484 | None | Δ of nt 72-80 | 256 | 256 | 12 | 150 | Menadione | |
| AH417 | IN480 | None | −1 FS at nt 422 | 256 | 256 | 24 | 180 | Menadione | |
| AH416 | IN476 | None | Δ of nt 395-398 | 256 | 256 | 48 | 170 | Menadione | |
a
Each of the original FA-susceptible clinical isolates had similar MICs for KAN, STR, and FA and similar doubling times in LB.
b
None, wild type. FS, frameshift mutation.
c
Doubling time (generation time) in minutes during exponential growth in LB.
d
Auxotrophy tested for hemin, menadione, thymine, and thymidine. −, nonauxotrophic.
e
Number of independent isolates with same genotype and phenotype.