Table 5.
Results of antimicrobial susceptibility testing (minimum inhibitory concentration, in mg/L) for C. difficile isolates from SAC.
| Isolate (RT) | Antimicrobials | MEZ | VAN | MOX | CIP | AMP | PEN | AMC | MEP | ERY | CLI | CHL | TET | LZD |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| BP/ECOFF (mg/L) | >2 a | >2 a | ≤2/≥8 b | 32 c | ≤0.5/≥2 b | ≤0.5/≥2 b | ≤4/2/≥16/8 b | ≤4/≥16 b | 4 c | ≤2/≥8 b | ≤8/≥32 b | ≤4/≥16 b | - | |
| 19S0105 (RT AI-75) | 0.19 | 0.75 | 1.5 | >32 | 1.5 | 1.5 | 0.75 | 1.5 | 2 | 8 | 12 | 0.38 | 3 | |
| 19S0136 (RT 078) | 0.125 | 0.75 | >32 | >32 | 0.75 | 1.5 | 0.38 | 0.75 | >256 | 2 | 6 | 16 | 3 | |
| 19S0160 (RT 015) | 0.38 | 0.75 | 1.5 | >32 | 1 | 1 | 1 | 1.5 | 2 | 12 | 6 | 0.38 | 6 | |
| 19S0161 (RT 015) | 0.125 | 0.75 | 1 | >32 | 1.5 | 1 | 0.75 | 1.5 | 2 | 12 | 6 | 0.38 | 4 | |
| 19S0260 (RT 002/2) | 0.38 | 1 | 1.5 | >32 | 1.5 | 1.5 | 0.5 | 1.5 | 2 | 8 | 8 | 0.19 | 3 | |
| 19S0262 (RT 002/2) | 0.38 | 0.75 | 1.5 | >32 | 1.5 | 1.5 | 0.75 | 1.5 | 2 | 8 | 8 | 0.25 | 3 | |
| 19S0264 (RT 002/2) | 0.38 | 0.75 | 1.5 | >32 | 1 | 1 | 0.5 | 1 | 2 | 12 | 8 | 0.094 | 3 | |
| 19S0266 (RT 029) | 0.38 | 1 | 1 | >32 | 3 | 4 | 0.75 | 1.5 | 2 | 6 | 8 | 0.5 | 8 | |
RT: Ribotype, BP: Breakpoints, ECOFF: Epidemiological cut-off values. MEZ: metronidazole, VAN: vancomycin, MOX: moxifloxacin, CIP: ciprofloxacin, AMP: ampicillin, PEN: penicillin, AMC: amoxicillin-clavulanate, MEP: meropenem, ERY: erythromycin, CLI: clindamycin, CHL: chloramphenicol, TET: tetracycline, LZD: linezolid. Etest® provides a continuous scale for the determination of MIC values. Therefore, results can be obtained that are in-between the conventional two-fold dilutions. For interpretation, results were rounded to the next two-fold standard dilution if they were in between two steps as indicated by the instructions for Etest® [17]: green: susceptible or wild type, yellow: intermediate, red: resistant or non wild type. a Breakpoints according to EUCAST [18]. b Breakpoints according to CLSI; first values indicate breakpoints for susceptible isolates, second values indicate breakpoints for resistant isolates [19]. c Epidemiological cut-off values from EUCAST [20].