TABLE 3.
Antimicrobial susceptibility of 102 E. faecium isolatesa
| Isolate type | Agent | Rectal isolates
|
Clinical isolates
|
||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| MIC (mg/liter)
|
No. of isolates
|
MIC (mg/liter)
|
No. of isolates
|
||||||||||
| Range | 50% | 90% | S | I | R | Range | 50% | 90% | S | I | R | ||
| Ampicillin resistant | Ampicillin | 24-256 | 64 | 128 | — | — | 58 | 6->256 | 32 | 64 | — | — | 23 |
| Ciprofloxacin | 0.75->32 | >32 | >32 | 6 | 5 | 47 | 3->32 | >32 | >32 | 0 | 1 | 22 | |
| Linezolid | 0.75-2 | 1 | 1.5 | 58 | 0 | 0 | 0.5-1.5 | 1 | 1.5 | 23 | 0 | 0 | |
| Quinupristin/dalfopristin | 0.25-64 | 0.5 | 1.5 | 50 | 4 | 4 | 0.19-0.5 | 0.5 | 0.5 | 23 | 0 | 0 | |
| Vancomycin | 0.5-2 | 1 | 2 | 58 | 0 | 0 | 0.5-2 | 1.5 | 1.5 | 23 | 0 | 0 | |
| Teicoplanin | 0.094-2 | 0.25 | 1.5 | 58 | 0 | 0 | 0.064-1.5 | 0.19 | 0.5 | 23 | 0 | 0 | |
| Gentamicin | 2->1024 | 8 | 12 | 55 | — | 3 | 2-16 | 4 | 8 | 23 | — | 0 | |
| Ampicillin susceptible | Ampicillin | 0.75-4 | 3 | 4 | 8 | — | — | 0.064-8 | 1 | 8 | 13 | — | — |
| Ciprofloxacin | 0.38->32 | 0.75 | >32 | 5 | 3 | 1 | 0.38->32 | 1.5 | >32 | 5 | 4 | 4 | |
| Linezolid | 1-1.5 | 1 | 1.5 | 8 | 0 | 0 | 0.75-1.5 | 1 | 1.5 | 13 | 0 | 0 | |
| Quinupristin/dalfopristin | 0.38-2 | 1.5 | 2 | 8 | 0 | 0 | 0.38-2 | 0.5 | 2 | 13 | 0 | 0 | |
| Vancomycin | 1-2 | 2 | 2 | 8 | 0 | 0 | 0.5-2 | 1 | 2 | 13 | 0 | 0 | |
| Teicoplanin | 1.5-3 | 3 | 3 | 8 | 0 | 0 | 0.032-2 | 0.19 | 2 | 13 | 0 | 0 | |
| Gentamicin | 3-6 | 4 | 6 | 8 | — | 0 | 0.19-8 | 4 | 8 | 13 | — | 0 | |
a
50% and 90%, MIC for 50 and 90% of isolates, respectively. S, sensitive; I, intermediate; R, resistant, breakpoints defined by NCCLS. For gentamicin, high-level aminoglycoside resistance = MIC ≥ 512 mg/liter. There were 58 ampicillin-resistant and 8 ampicillin-susceptible rectal isolates and 23 ampicillin-resistant and 13 ampicillin-susceptible clinical isolates. —, no value possible (for ampicillin) or no criteria established by NCCLS (for gentamicin).