TABLE 1.
Clinical data and microbiological characteristics of blaIMP-8-harboring isolatesa
| Newborn | Bacterial isolate/day of isolationb/no. of days of NICU stay before isolation | Treatment/no. of days of treatment | Risk factor/GA/wt of newborn (g) | Antimicrobial susceptibility (MIC [μg/ml])c |
Pulsotype | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| AM | AMS | PTZ | FEP | CAZ | CTX | IMP | MEM | GEN | AKN | CIP | COL | TMS | |||||
| 1 | G2116/1/89 | MEM/21, COL/21, VAN/21 | Preterm birth/30 wks/870 | >32 | >32 | >128 | >64 | >64 | >64 | 8 | 16 | >16 | >64 | 1 | 2 | >320 | I |
| 2 | G1116/13/40 | AM/10, GEN/7, CTX/5, AKN/5, COL/8 | Preterm birth/28 wks/1,260 | >32 | >32 | >128 | 16 | >64 | >64 | 4 | 8 | >16 | >64 | 1 | 1 | >320 | I |
| G1216/28/56 | >32 | >32 | >128 | >64 | >64 | >64 | 8 | 8 | >16 | >64 | 1 | 1 | >320 | II | |||
| G1316/41/69 | >32 | >32 | >128 | >64 | >64 | >64 | 2 | 8 | >16 | >64 | 1 | 1 | >320 | I | |||
| 3 | G4116/28/41 | AM/10, GEN/7 | Term birth/40 wks/3,370 | >32 | >32 | >128 | >64 | >64 | >64 | 8 | 16 | >16 | >64 | 1 | 1 | >320 | I |
| 4 | G3116/28/8 | CTX/4, AKN/4 | Term birth/38 wks/3,210 | >32 | >32 | >128 | >64 | >64 | >64 | 8 | 8 | >16 | >64 | 1 | 2 | >320 | I |
| G3216/41/21 | >32 | >32 | >128 | >64 | >64 | >64 | 4 | 8 | 8 | 32 | <0.25 | 8 | >320 | III | |||
| 5 | G6116/43/16 | AM/5, GEN/5 | Preterm birth/34 wks/2,060 | >32 | >32 | >128 | >64 | >64 | >64 | 2 | 8 | >16 | >64 | 1 | 1 | >320 | I |
| 6 | G7116/43/28 | VAN/12, MEM/12 | Preterm birth/32 wks/1,610 | >32 | >32 | 128 | >64 | >64 | >64 | 2 | 8 | >16 | >64 | 1 | 1 | >320 | I |
| 7 | G5116/49/41 | Preterm birth/37 wks/2,500 | >32 | >32 | >128 | >64 | >64 | >64 | 2 | 8 | >16 | >64 | 1 | 1 | >320 | I | |
AM, ampicillin; AMS, ampicillin-sulbactam; PTZ, piperacillin-tazobactam; FEP, cefepime; CAZ, ceftazidime; CTX, cefotaxime; IMP, imipenem; MEM, meropenem; GEN, gentamicin; AKN, amikacin; CIP, ciprofloxacin; COL, colistin; TMS, trimethoprim-sulfamethoxazole; VAN, vancomycin; GA, gestational age.
For the data representing the day of isolation, day 1 corresponds to the index case; the other days of isolation were determined with respect to that of the index case.
MICs for IMP, MEM, and COL were assessed by manual procedures, whereas those of the others were assessed by automated methods (Vitek 2). Data corresponding to the mcr-1-harboring isolate are indicated in bold.