TABLE 1.
E. coli strain/plasmid gene | Relevant features | Plasmid containing PMQRa gene | Ciprofloxacin susceptibilityb | MIC (μg/ml)c |
MBC (μg/ml) |
||||||
---|---|---|---|---|---|---|---|---|---|---|---|
CIP | LVX | MXF | NFX | CIP | LVX | MXF | NFX | ||||
ATCC 25922 | Wild type | None | S | 0.002 | 0.008 | 0.008 | 0.015 | 0.015 | 0.03 | 0.015 | 0.03 |
ATCC/qnrA | Wild type | pBK-QnrA1 | S | 0.125 | 0.5 | 0.25 | 0.5 | 0.125 | 0.5 | 0.5 | 1 |
ATCC/qnrB | Wild type | pBK-QnrB1 | S | 0.125 | 0.125 | 0.25 | 0.25 | 0.125 | 0.25 | 1 | 0.5 |
ATCC/qnrS | Wild type | pBK-QnrS1 | S | 0.125 | 0.5 | 0.25 | 0.5 | 0.25 | 0.5 | 0.25 | 1 |
ATCC 25922-S83L | GyrA Ser83Leu | None | S | 0.125 | 0.125 | 0.06 | 0.125 | 0.125 | 0.25 | 0.125 | 0.5 |
ATCC-S83L/qnrA | GyrA Ser83Leu | pBK-QnrA1 | S | 0.5 | 0.5 | 0.5 | 2 | 0.5 | 0.5 | 0.5 | 2 |
ATCC-S83L/qnrB | GyrA Ser83Leu | pBK-QnrB1 | S | 0.5 | 0.25 | 0.5 | 1 | 0.5 | 0.5 | 0.5 | 1 |
ATCC-S83L/qnrS | GyrA Ser83Leu | pBK-QnrS1 | S | 1 | 1 | 1 | 2 | 1 | 2 | 2 | 4 |
ATCC 25922-S80R | ParC Ser80Arg | None | S | 0.004 | 0.008 | 0.008 | 0.03 | 0.004 | 0.008 | 0.008 | 0.03 |
ATCC-S80R/qnrA | ParC Ser80Arg | pBK-QnrA1 | S | 0.25 | 0.25 | 0.5 | 0.5 | 0.25 | 0.5 | 0.5 | 2 |
ATCC-S80R/qnrB | ParC Ser80Arg | pBK-QnrB1 | S | 0.125 | 0.25 | 0.5 | 0.5 | 0.25 | 0.5 | 0.5 | 0.5 |
ATCC-S80R/qnrS | ParC Ser80Arg | pBK-QnrS1 | S | 0.125 | 0.25 | 0.25 | 0.5 | 0.25 | 0.25 | 0.5 | 0.5 |
ATCC 25922-S83L-S80R | GyrA Ser83Leu, ParC Ser80Arg | None | S | 0.25 | 0.25 | 0.25 | 2 | 2 | 0.25 | 0.25 | 2 |
ATCC-S83L-S80R/qnrA | GyrA Ser83Leu, ParC Ser80Arg | pBK-QnrA1 | I | 2 | 2 | 2 | 8 | 4 | 4 | 4 | 64 |
ATCC-S83L-S80R/qnrB | GyrA Ser83Leu, ParC Ser80Arg | pBK-QnrB1 | S | 1 | 1 | 1 | 4 | 2 | 1 | 2 | 4 |
ATCC-S83L-S80R/qnrS | GyrA Ser83Leu, ParC Ser80Arg | pBK-QnrS1 | I | 2 | 4 | 2 | 8 | 4 | 4 | 4 | 16 |
PMQR, plasmid-mediated quinolone resistance.
S and I, susceptible and intermediate susceptibility, respectively, according to CLSI guidelines (2).
MICs determined by microdilution for ciprofloxacin (CIP), levofloxacin (LVX), moxifloxacin (MXF), and norfloxacin (NFX).