Table 1.
Characteristics of the study isolates.
| Isolate | Ward | Specimen | a Susceptibility status to antimicrobials | PFGE | Agar dilution MEM MIC (mg/L) | Highest MEM concentration of growth in population analyses (mg/L) | b Agar dilution MIC (mg/L) of MEM grown subpopulations |
|---|---|---|---|---|---|---|---|
| Ab1 | ORL | Blood | SAM, CIP, COL, MEM | I | 4 | 16 | 32 |
| Ab2 | Neurosurgery | Blood | GEN, TOB, CIP, SAM, MEM, COL | II | 1 | 8 | 1 |
| Ab3 | Pathology | Urine | GEN, TOB, SAM, MEM, COL | I | 2 | 8 | 1 |
| Ab4 | Pulmonary | Sputum | GEN, SAM, MEM, COL | I | 4 | 16 | 2 |
| Ab5 | Pathology | CSF | GEN, TOB, SAM, MEM, COL | III | 2 | 32 | > 32 |
a CIP, ciprofloxacin; COL, colistin; GEN, gentamicin; MEM, meropenem; MIC, minimum inhibitory concentration; PFGE, pulsed field gel electrophoresis; SAM, ampicillin/sulbactam; TOB, tobramycin; b These MICs were estimated after one week of daily subcultures in antibiotic-free medium.