TABLE 1.
Bacterial strains used in this study
| Strain | Propertiesc | Resistance to new FQa | Amino acid substitution inb: |
|
|---|---|---|---|---|
| GyrA | GyrB | |||
| ATCC 43603 | TcdA− TcdB−; clinical isolate from a newborn carrier (Belgium) | − | None | None |
| ATCC 43603-M1 | TcdA− TcdB−; in vitro moxifloxacin-resistant mutant of ATCC 43603 | + | Thr82→Ile (ACT→ATT) | Ser366→Ala (TCA→GCA) |
| CD196 (CIP10793) | TcdA+ TcdB+; historical NAP1/027, clinical isolate from CDI (France) | − | None | None |
| CD196-M1 | TcdA+ TcdB+; in vitro moxifloxacin-resistant mutant from CD196 | + | Thr82→Ile (ACT→ATT) | Gln434→Lys (CAA→AAA) |
| CD07-259 | TcdA+ TcdB+; current NAP1/027, clinical isolate from CDI (Nord-Pas-de-Calais, France) | + | Thr82→Ile (ACT→ATT) | None |
| 6296 | TcdA+ TcdB+; current NAP1/027, REA-type BI-11, clinical isolate from CDI (United States) | + | None | None |
| 6425 | TcdA+ TcdB+; current NAP1/027, REA type BI-12, clinical isolate from CDI (United States) | + | Thr82→Ile (ACT→ATT) | None |
a
New FQ, new fluoroquinolone moxifloxacin; −, susceptible strain (MIC < 8 μg/ml); +, resistant strain (MIC ≥ 8 μg/ml).
b
Compared to the GyrA and the GyrB sequences in strain 630.
c
REA, restriction endonuclease analysis.