TABLE 1.
Features of the MCR-1-producing colistin-resistant E. coli isolates and patient characteristicsa
| Strain no. | Date of isolation | Site of isolation | Gender | Age range of the patient (yrs) | Origin (city) | MIC of colistin (μg/ml) | β-lactam resistance phenotype | PFGE profile | Sequence type | mcr-1-positive plasmid type | mcr-1-positive plasmid size (ca. kb) | Coresistance markers |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Af23 | March 2014 | Blood | M | 50–59 | Pretoria | 4 | Penicillinase (TEM-1) | B | ST10 | IncI2 | 70 | CIP, TET, SXT |
| Af24 | March 2014 | Pus | F | 40–49 | Johannesburg | 4 | Penicillinase (TEM-1) | C | ST1007 | IncI2 | 65 | CIP, TET, SXT |
| Af31 | October 2014 | Urine | F | 60–69 | Johannesburg | 8 | Susceptible | A | ST624 | IncHI2 | 150 | CIP, TET, SXT, CHL, FLO, KAN |
| Af40 | March 2015 | Wound | F | 60–69 | Johannesburg | 4 | ESBL (CTX-M-55) | D | ST57 | IncI2 | ND | CIP, TET, CHL, FOS, KAN, TOB, SXT |
| Af45 | May 2015 | Urine | F | 60–69 | Johannesburg | 8 | Susceptible | E | ST101 | IncI2 | 70 | TET, SXT |
| Af48 | May 2015 | Urine | F | 60–69 | Johannesburg | 4 | AmpC (CMY-2) | A | ST624 | IncX4 | 30 | CIP, TET, SXT, CHL |
| Af49 | May 2015 | Urine | F | 30–39 | Pretoria | 4 | ESBL (CTX-M-55) | F | ST226 | ND | ND | CIP, TET, SXT, CHL, FOS, KAN, TOB |
a
PFGE, pulsed-field gel electrophoresis; M, male; F, female; ND, not determined; CIP, ciprofloxacin; TET, tetracycline; SXT, trimethoprim plus sulfamethoxazole; CHL, chloramphenicol; FLO, florfenicol; KAN, kanamycin; TOB, tobramycin; FOS, fosfomycin; CHL, chloramphenicol.