TABLE 6.
Spontaneous mutation rates of N. meningitidis (MC) H44/76 and M1080 and N. gonorrhoea (GC) FA1090 wild-type and mutY mutant strains assessed by rifampin and nalidixic acid resistancea
| Strain | No. of Rifr mutants per 108 CFU
|
No. of Nalr mutants per 108 CFU
|
||||
|---|---|---|---|---|---|---|
| Median | (± 1 quartile) | Fold increase | Median | (± 1 quartile) | Fold increase | |
| Mc H44/76 wild type | <0.1 | (0.0/0.3) | 1 | 0.8 | (0.6/0.9) | 1 |
| Mc H44/76 mutY | 25.0 | (18.1/35.0) | 63b | 100.5 | (89.8/114.5) | 138 |
| Mc M1080 wild type | 7.1 | (3.5/8.9) | 1 | ND | ND | |
| Mc M1080 mutY | 44.1 | (39.7/73.8) | 6 | ND | ND | |
| Gc FA1090 wild type | 0.4 | (0.1/0.6) | 1 | ND | ND | |
| Gc FA1090 mutY | 9.3 | (8.8/12.3) | 23 | ND | ND | |
a
The results are given as the medians of 10 and 7 independent measurements, respectively, for Rifr and Nalr mutants. ND, not done.
b
The median was reported as <0.1, so the average of 15 independent measurements (= 0.4) was used to calculate fold induction.