TABLE 3.
Susceptibility of Gardnerella strains before and after passaging 8 to 9 times with sub-MICs of MZD or MDZ-OHa
| Gardnerella strain | Passaging antibiotic | MIC (μg/mL) |
MBEC (μg/mL) when passaged with: |
||||||
|---|---|---|---|---|---|---|---|---|---|
| Before passaging |
After passaging |
||||||||
| MDZ | MDZ-OH | PM-477 | MDZ | MDZ-OH | PM-477 | MDZ | PM-477 | ||
| G. vaginalis | |||||||||
| ATCC 14018T | MDZ | 8 | 2 | 0.06 | >512 | >512 | 0.13 | >2,048 | 2–8 |
| UGent 09.07b | MDZ-OH | 64 | 8 | 0.25 | >2,048 | >512 | 0.25 | >2,048 | 2–4 |
| UGent BV50 | MDZ-OH | 32 | 4 | 0.5 | >2,048 | >512 | 0.25 | >2,048 | 1–8 |
| G. swidsinskii | |||||||||
| GS 9838-1T | MDZ-OH | 256 | 16 | 0.03 | >512 | >512 | 0.06 | >2,048 | 2 |
| UGent BV 7.1 | MDZ-OH | 256 | 32 | 0.25 | >2,048 | >512 | 0.06 | >2,048 | 2 |
| G. piotii UGent 18.01T | MDZ-OH | 32 | 8 | 1 | >2,048 | >512 | 2 | >2,048 | <1 |
a
All MICs were determined after 48 h of incubation. MBEC, minimal biofilm radication concentration; MDZ, metronidazole; MDZ-OH, hydroxy metabolite of MDZ; T, after strain designation indicates a type strain.
b
G. vaginalis UGent 09.07 was passaged only 8 times with MDZ-OH.