Table 2.
Class-specific cross-resistance to nitrofurans in Clostridium difficilea
| Agent | Parent strain | Mutant | MIC (fold increase) | |||
|---|---|---|---|---|---|---|
| NFZ | NIF | FZD | NFT | |||
| NFZ | CD196 | MK-2131 | 4 | Noneb | 16 | None |
| CD196 | MK-2631 | 8 | 8 | 16 | 4 | |
| BAA-1875 | MK-2634 | 4 | 8 | 16 | None | |
| R20291 | MK-2137 | 4 | 4 | 16 | None | |
| NIF | CD196 | MK-2132 | 8 | 4 | 16 | None |
| CD196 | MK-2632 | 8 | 4 | 16 | None | |
| BAA-1875 | MK-2135 | 4 | 4 | 8 | 4 | |
| BAA-1875 | MK-2635 | 4 | 8 | 16 | None | |
| NFT | CD196 | MK-2133 | 8 | 4 | 4 | 2 |
| BAA-1875 | MK- 2636 | 8 | 8 | 8 | 8 | |
MIC, minimum inhibitory concentration; NFZ, nitrofurazone; NIF, nifuroxazide; FZD, furazolidone; NFT, nitrofurantoin.
a
No cross-resistance to nitazoxanide and metronidazole was observed.
b
‘None’ indicates that no fold increase was observed.